3.5. General Procedure for Mixed Double-Michael Reaction
The N-tosylamido alcohol pro-nucleophile (1 mmol), DPPP (84.2 mg, 0.2 mmol), and CH3CN (5 mL) were placed in a dried two-neck round-bottom flask (25 mL) equipped with a magnetic stirrer bar. The mixture was brought to reflux in an oil bath (external temperature: 90 °C). A solution of the electron-deficient acetylene (1.2 mmol) in CH3CN (1 mL) was added into the flask over 1 h using a syringe pump. [In the case of ethynyl p-tolyl sulfone, the acetylene (1.2 mmol) was added to the flask over 2 h via syringe pump.] The reaction mixture was stirred overnight under reflux, under a positive pressure of argon, monitoring with TLC (20% EtOAc in hexanes). The resulting reaction mixture was concentrated in vacuo and purified by FCC on silica gel (20% EtOAc in hexanes) to yield the cyclized product.
Methyl 2-[(2S,4S)-4-isopropyl-3-tosyloxazolidin-2-yl]acetate (3a). 59% yield; white solid; IR (CH2Cl2) νmax 2960.7, 1741.9, 1598.1, 1351.2, 1164.7 cm–1; 1H-NMR (400 MHz, CDCl3) δ 7.68 (d, J = 8.4 Hz, 2H), 7.29 (d, J = 8.0 Hz, 2H), 5.23 (dd, J = 8.8, 3.2 Hz, 1H), 3.69 (dd, J = 9.2, 2.4 Hz, 1H), 3.64 (s, 3H), 3.35 (ddd, J = 7.9, 6.1, 2.1 Hz, 1H), 3.00–3.07 (m, 2H), 2.62 (dd, J = 15.8, 8.6 Hz, 1H), 2.36 (s, 3H), 1.78–1.86 (m, 1H), 0.95 (d, J = 6.8 Hz, 3H), 0.87 (d, J = 6.8 Hz, 3H); 13C-NMR (100 MHz, CDCl3) δ 169.9, 144.4, 133.7, 130.0, 127.9, 88.8, 67.8, 64.9, 51.8, 41.8, 31.3, 21.5, 19.5, 18.4; HRMS (ESI+) calcd for [C16H23NO5S]+: m/z 342.1370, found 342.1364.
Ethyl 2-[(2S,4S)-4-isopropyl-3-tosyloxazolidin-2-yl]acetate (3b). 75% yield; yellow oil; IR (CH2Cl2) νmax 2964.4, 1736.0, 1598.0, 1351.6, 1165.3 cm–1; 1H-NMR (400 MHz, CDCl3) δ 7.65 (d, J = 8.4 Hz, 2H), 7.25 (d, J = 8.0 Hz, 2H), 5.21 (dd, J = 8.8, 3.2 Hz, 1H), 4.07 (q, J = 7.2 Hz, 2H), 3.66 (dd, J = 9.0, 2.2 Hz, 1H), 3.32 (ddd, J = 7.7, 6.1, 1.9 Hz, 1H), 2.96–3.04 (m, 2H), 2.58 (dd, J = 15.8, 8.6 Hz, 1H), 2.32 (s, 3H), 1.75–1.84 (m, 1H), 1.17 (t, J = 7.0 Hz, 3H), 0.92 (d, J = 6.8 Hz, 3H), 0.84 (d, J = 6.8 Hz, 3H); 13C-NMR (100 MHz, CDCl3) δ 169.5, 144.3, 133.7, 130.0, 127.9, 88.9, 67.8, 64.8, 60.7, 42.0, 31.3, 21.4, 19.5, 18.4, 14.1; HRMS (ESI+) calcd for [C17H25NO5S]+: m/z 356.1526, found 356.1518.
Benzyl 2-[(2S,4S)-4-isopropyl-3-tosyloxazolidin-2-yl]acetate (3c). 63% yield; yellow oil; IR (CH2Cl2) νmax 3031.4, 2962.6, 1738.7, 1597.8, 1351.2, 1164.7 cm–1; 1H-NMR (400 MHz, CDCl3) δ 7.73 (d, J = 8.0 Hz, 2H), 7.30–7.36 (m, 7H), 5.35 (dd, J = 8.6, 3.0 Hz, 1H), 5.15 (s, 2H), 3.75 (dd, J = 9.0, 2.2 Hz, 1H), 3.42 (ddd, J = 7.7, 5.9, 2.1 Hz, 1H), 3.09–3.17 (m, 2H), 2.75 (dd, J = 15.8, 8.6 Hz, 1H), 2.40 (s, 3H), 1.84–1.91 (m, 1H), 1.01 (d, J = 6.8 Hz, 3H), 0.92 (d, J = 6.8 Hz, 3H); 13C-NMR (100 MHz, CDCl3) δ 169.5, 144.4, 135.7, 133.8, 130.1, 130.0, 128.6, 128.3, 128.0, 88.9, 67.9, 66.6, 65.0, 42.0, 31.4, 21.6, 19.6, 18.5. HRMS (ESI+) calcd for [C22H27NO5S]+: m/z 418.1683, found 418.1671.
Phenyl 2-[(2S,4S)-4-isopropyl-3-tosyloxazolidin-2-yl]acetate (3d). 22% yield; yellow oil; IR (CH2Cl2) νmax 3065.2, 2963.8, 1758.9, 1594.3, 1351.3, 1306.6, 1164.5 cm–1; 1H-NMR (400 MHz, CDCl3) δ 7.77 (d, J = 8.4 Hz, 2H), 7.34–7.37 (m, 4H), 7.21–7.25 (m, 1H), 7.12 (d, J = 1.2 Hz, 2H), 5.42 (dd, J = 8.2, 3.4 Hz, 1H), 3.82 (dd, J = 9.2, 2.4 Hz, 1H), 3.44 (ddd, J = 7.8, 6.0, 2.0 Hz, 1H), 3.34 (dd, J = 15.8, 3.4 Hz, 1H), 3.16 (dd, J = 9.2, 6.4 Hz, 1H), 2.93 (dd, J = 15.8, 8.2 Hz, 1H), 2.43 (s, 3H), 1.93–1.99 (m, 1H), 1.05 (d, J = 6.8 Hz, 3H), 0.98 (d, J = 6.8 Hz, 3H); 13C-NMR (100 MHz, CDCl3) δ 168.2, 150.5, 144.5, 133.7, 130.1 , 129.4, 128.1, 126.0, 121.6, 88.9, 67.9, 65.0, 42.2, 31.4, 21.6, 19.6, 18.5; HRMS (ESI+) calcd for [C21H25NO5S]+: m/z 404.1526, found 404.1510.
1-[(2S,4S)-4-Isopropyl-3-tosyloxazolidin-2-yl]propan-2-one (3e). 53% yield; light yellow oil; IR (CH2Cl2) νmax 2963.3, 1719.4, 1597.9, 1348.5, 1164.1 cm–1; 1H-NMR (400 MHz, CDCl3) δ 7.65 (d, J = 8.4 Hz, 2H), 7.27 (d, J = 8.4 Hz, 2H), 5.19 (dd, J = 8.4, 2.4 Hz, 1H), 3.66 (dd, J = 9.0, 1.8 Hz, 1H), 3.31 (ddd, J = 7.6, 6.0, 1.6 Hz, 1H), 3.12 (dd, J = 17.0, 2.6 Hz, 1H), 2.99 (dd, J = 9.0, 6.2 Hz, 1H), 2.78 (dd, J = 16.8, 8.4 Hz, 1H), 2.35 (s, 3H), 2.13, (s, 3H), 1.76–1.85 (m, 1H), 0.94 (d, J = 6.8 Hz, 3H), 0.86 (d, J = 6.8 Hz, 3H); 13C-NMR (100 MHz, CDCl3) δ 205.1, 144.3, 133.6, 130.0, 127.9, 88.3, 67,8, 64.7, 50.3, 31.4, 30.7, 21.5, 19.5, 18.4; HRMS (ESI+) calcd for [C16H23NO4S]+: m/z 326.1421, found 326.1416.
2-[(2S,4S)-4-Isopropyl-3-tosyloxazolidin-2-yl]-1-phenylethanone (3f). 55% yield; yellow solid; IR (CH2Cl2) νmax 3062.5, 2963.3, 1686.1, 1597.3, 1349.4, 1164.5 cm–1; 1H-NMR (400 MHz, CDCl3) δ 7.95 (d, J = 6.8 Hz, 2H), 7.72 (d, J = 8.0 Hz, 2H), 7.41–7.53 (m, 3H), 7.31 (d, J = 12.0 Hz, 2H), 5.45 (dd, J = 8.8, 2.0 Hz, 1H), 3.74 (dq, J = 12.8, 2.0 Hz, 2H), 3.35–3.43 (m, 2H), 3.06 (dd, J = 8.8, 6.0 Hz, 1H), 2.37 (s, 3H), 1.86–1.95 (m, 1H), 1.02 (d, J = 7.2 Hz, 3H), 0.94 (d, J = 6.8 Hz, 3H); 13C-NMR (100 MHz, CDCl3) δ 196.6, 144.4, 136.6, 133.6, 133.5, 130.1, 128.7, 128.2, 128.0, 89.0, 67.9, 64.8, 45.9, 31.5, 21.5, 19.6, 18.5; HRMS (ESI+) calcd for [C21H25NO4S]+: m/z 388.1577, found 388.1568.
1-(3,4-Dichlorophenyl)-2-[(2S,4S)-4-isopropyl-3-tosyloxazolidin-2-yl]ethanone (3g). 28% yield; yellow solid; IR (CH2Cl2) νmax 3064.1, 2963.2, 1691.3, 1584.2, 1350.0, 1164.8 cm–1; 1H-NMR (400 MHz, CDCl3) δ 8.02 (d, J = 2.0 Hz, 2H), 7.78 (dd, J = 8.4, 2.0 Hz, 1H), 7.72 (d, J = 8.4 Hz, 2H), 7.53 (d, J = 8.4 Hz, 1H), 7.33 (d, J = 8.4 Hz, 2H), 5.38 (dd, J = 8.4, 2.0 Hz, 1H), 3.76 (dd, J = 9.2, 1.6 Hz, 1H), 3.71 (dd, J = 16.6, 2.2 Hz, 1H), 3.39 (ddd, J = 7.6, 6.0, 1.6 Hz, 1H), 3.06 (dd, J = 9.0, 6.2 Hz, 1H), 3.06 (dd, J = 9.0, 6.2 Hz, 1H), 2.41 (s, 3H), 1.85–1.92 (m, 1H), 1.02 (d, J = 7.2 Hz, 3H), 0.94 (d, J = 6.8 Hz, 3H); 13C-NMR (100 MHz, CDCl3) δ 194.5, 144.5, 138.0, 136.1, 133.5, 133.4, 130.8, 130.2, 130.1, 128.0, 127.4, 88.7, 67.9, 64.8, 46.0, 31.5, 21.6, 19.6, 18.5; HRMS (ESI+) calcd for [C21H23Cl2NO4S]+: m/z 456.0798, found 456.0756.
1-(3,4-Dimethoxyphenyl)-2-[(2S,4S)-4-isopropyl-3-tosyloxazolidin-2-yl]ethanone (3h). 58% yield; yellow oil; IR (CH2Cl2) νmax 3068.2, 2962.9, 1673.5, 1595.7, 1347.3, 1164.0 cm–1; 1H-NMR (400 MHz, CDCl3) δ 7.66 (d, J = 8.4 Hz, 2H), 7.54 (dd, J = 8.4, 2.0 Hz, 1H), 7.25 (d, J = 8.4 Hz, 2H), 5.36 (dd, J = 8.8, 2.0 Hz, 1H), 3.84 (s, 3H), 3.83 (s, 3H), 3.61–3.70 (m, 2H), 3.33 (ddd, J = 7.5, 6.1, 1.7 Hz, 1H), 3.24 (dd, J = 16.4, 8.8 Hz, 1H), 2.32 (s, 3H), 1.80–1.89 (m, 1H), 0.95 (d, J = 7.2 Hz, 3H), 0.87 (d, J = 6.8 Hz, 3H); 13C-NMR (100 MHz, CDCl3) δ 195.1, 153.6, 149.0, 144.3, 133.6, 130.0, 129.8, 128.0, 123.2, 110.2, 89.2, 67.8, 64.7, 56.0, 55.9, 45.4, 31.4, 21.4, 19.6, 18.4; HRMS (ESI+) calcd for [C23H29NO6S]+: m/z 448.1788, found 448.1790.
1-(4-Fluorophenyl)-2-[(2S,4S)-4-isopropyl-3-tosyloxazolidin-2-yl]ethanone (3i). 63% yield; brown oil; IR (CH2Cl2) νmax 3068.8, 2963.8, 1686.0, 1597.3, 1349.6, 1164.7 cm–1; 1H-NMR (400 MHz, CDCl3) δ 7.97 (t, J = 6.8 Hz, 2H), 7.70 (d, J = 7.6 Hz, 2H), 7.30 (d, J = 8.0 Hz, 2H), 7.09 (t, J = 8.0 Hz, 2H), 5.40 (dd, J = 8.6, 1.8 Hz, 1H), 3.67–3.74 (m, 2H), 3.29–3.40 (m, 2H), 3.04 (dd, J = 8.8, 6.4 Hz, 1H), 2.37 (s, 3H), 1.84–1.92 (m, 1H), 1.00 (d, J = 6.8 Hz, 3H), 0.92 (d, J = 6.8 Hz, 3H); 13C-NMR (100 MHz, CDCl3) δ 195.0, 167.2, 164.6, 144.4, 133.6, 133.1, 131.0, 130.1, 130.0, 128.0, 115.8, 115.6, 89.0, 67.9, 64.8, 45.8, 31.5, 21.5, 19.6, 18.5; HRMS (ESI+) calcd for [C21H24FNO4S]+: m/z 406.1483, found 406.1477.
2-[(2S,4S)-4-Isopropyl-3-tosyloxazolidin-2-yl]-1-(naphth-1-yl)ethanone (3j). 70% yield; yellow oil; IR (CH2Cl2) νmax 3051.1, 2963.2, 1680.3, 1595.9, 1348.4, 1164.0 cm–1; 1H-NMR (400 MHz, CDCl3) δ 8.72 (d, J = 8.4 Hz, 1H), 7.96–7.98 (m, 2H), 7.84 (d, J = 8.0 Hz, 1H), 7.77 (d, J = 8.0 Hz, 2H), 7.48–7.59 (m, 3H), 7.27 (d, J = 11.6 Hz, 2H), 5.55 (dd, J = 8.8, 2.4 Hz, 1H), 3.92 (dd, J = 16.6, 2.2 Hz, 1H), 3.79 (dd, J = 9.0, 1.8 Hz, 1H), 3.45 (ddd, J = 13.5, 6.7, 4.5 Hz, 2H), 3.10 (dd, J = 9.0, 6.2 Hz, 1H), 2.37 (s, 3H), 1.90–1.98 (m, 1H), 1.05 (d, J = 6.8 Hz, 3H), 0.96 (d, J = 6.4 Hz, 3H); 13C-NMR (100 MHz, CDCl3) δ 200.3, 144.4, 135.0, 134.0, 133.7, 133.3, 130.2, 130.1, 128.5, 128.1, 126.6, 126.0, 124.4, 89.4, 68.0, 64.9, 49.1, 31.6, 21.5, 19.7, 18.6; HRMS (ESI+) calcd for [C25H27NO4S]+: m/z 438.1734, found 438.1730.
2-[(2S,4S)-4-Isopropyl-3-tosyloxazolidin-2-yl]-1-(thien-2-yl)ethanone (3k). 37% yield; brown solid; IR (CH2Cl2) νmax 3102.5, 2963.1, 1660.1, 1597.6, 1348.8, 1164.0 cm–1; 1H-NMR (400 MHz, CDCl3) δ 7.77 (d, J = 1.2 Hz, 1H), 7.72 (d, J = 8.4 Hz, 2H), 7.64 (dd, J = 5.0, 1.0 Hz, 1H), 7.32 (d, J = 8.0 Hz, 2H), 7.12 (dd, J = 5.0, 3.8 Hz, 1H), 5.39 (dd, J = 8.4, 2.4 Hz, 1H), 3.75 (dd, J = 9.2, 2.0 Hz, 1H), 3.64 (dd, J = 15.8, 2.2 Hz, 1H), 3.39 (ddd, J = 7.6, 6.0, 1.8 Hz, 1H), 3.30 (dd, J = 16.0, 8.4 Hz, 1H), 3.06 (dd, J = 8.8, 6.0 Hz, 1H), 2.40 (s, 3H), 1.86–1.95 (m, 1H), 1.01 (d, J = 6.8 Hz, 3H), 0.94 (d, J = 6.8 Hz, 3H); 13C-NMR (100 MHz, CDCl3) δ 189.1, 144.4, 144.1, 134.4, 133.6, 132.8, 130.1, 128.3, 128.0, 89.0, 67.9, 64.8, 46.5, 31.5, 21.6, 19.6, 18.5; HRMS (ESI+) calcd for [C19H23NO4S2]+: m/z 394.1141, found 394.1152.
Methyl 2-[(2S,4S)-4-methyl-3-tosyloxazolidin-2-yl]acetate (4a). 68% yield; white solid; IR (CH2Cl2) νmax 2983.0, 1739.9, 1598.2, 1350.8, 1164.8 cm–1; 1H-NMR (400 MHz, CDCl3) δ 7.69 (d, J = 1.6 Hz, 2H), 7.30 (d, J = 8.0 Hz, 2H), 5.29 (dd, J = 8.8, 2.8 Hz, 1H), 3.65–3.70 (m, 4H), 3.52 (dd, J = 9.0, 4.2 Hz, 1H), 3.41 (dd, J = 8.8, 6.0 Hz, 1H), 3.04 (dd, J = 16.0, 3.2 Hz, 1H), 2.69 (dd, J = 15.6, 8.8 Hz, 1H), 2.38 (s, 3H), 1.29 (d, J = 6.4 Hz, 3H); 13C-NMR (100 MHz, CDCl3) δ 169.9, 144.4, 133.6, 130.0, 127.8, 127.1, 88.9, 71.8, 55.1, 51.9, 51.8, 42.1, 21.5, 20.9; HRMS (ESI+) calcd for [C14H19NO5S]+: m/z 314.1057, found 314.1050.
Ethyl 2-[(2S,4S)-4-methyl-3-tosyloxazolidin-2-yl]acetate (4b). 68% yield; white solid; IR (CH2Cl2) νmax 2982.7, 1736.4, 1598.3, 1351.1, 1164.9 cm–1; 1H-NMR (400 MHz, CDCl3) δ 7.65 (d, J = 8.4 Hz, 2H), 7.26 (d, J = 8.0 Hz, 2H), 5.25 (dd, J = 8.6, 3.0 Hz, 1H), 4.08 (q, J = 7.1 Hz, 2H), 3.65 (ddd, J = 8.3, 4.3, 2.1 Hz, 1H), 3.48 (dd, J = 9.0, 4.2 Hz, 1H), 3.37 (dd, J = 8.8, 6.0 Hz, 1H), 2.98 (dd, J = 15.8, 3.0 Hz, 1H), 2.63 (dd, J = 15.6. 8.8 Hz, 1H), 2.33 (s, 3H), 1.24 (d, J = 6.4 Hz, 3H), 1.18 (t, J = 7.2 Hz, 3H); 13C-NMR (100 MHz, CDCl3) δ 169.4, 144.3, 133.6, 130.0, 127.8, 127.1, 88.9, 71.8, 60.7, 55.0, 42.2, 21.4, 20.8, 14.1; HRMS (ESI+) calcd for [C15H21NO5S]+: m/z 328.1213, found 328.1207.
Benzyl 2-[(2S,4S)-4-methyl-3-tosyloxazolidin-2-yl]acetate (4c). 64% yield; yellow oil; IR (CH2Cl2) νmax 3064.8, 2979.9, 1738.1, 1598.1, 1351.1, 1165.1 cm–1; 1H-NMR (400 MHz, CDCl3) δ 7.73 (d, J = 8.4 Hz, 2H), 7.28–7.36 (m, 6H), 5.38 (dd, J = 8.6, 3.0 Hz, 1H), 5.16 (s, 2H), 3.73 (ddd, J = 8.5, 4.1, 2.1 Hz, 1H), 3.55 (dd, J = 8.8, 4.0 Hz, 1H), 3.46 (dd, J = 9.0, 6.2 Hz, 1H), 3.14 (dd, J = 15.8, 3.0 Hz, 1H), 2.79 (dd, J = 15.8, 8.6 Hz, 1H), 2.41 (s, 3H), 1.32 (d, J = 6.4 Hz, 3H); 13C-NMR (100 MHz, CDCl3) δ 169.4, 144.4, 135.7, 133.6, 130.1, 130.0, 128.6, 128.5, 128.3, 127.9, 127.2, 89.0, 71.9, 66.6, 55.2, 42.3, 21.6, 20.9; HRMS (ESI+) calcd for [C20H23NO5S]+: m/z 390.1317, found 390.1346.
Phenyl 2-[(2S,4S)-4-methyl-3-tosyloxazolidin-2-yl]acetate (4d). 14% yield; yellow oil; IR (CH2Cl2) νmax 3068.2, 2980.3, 1758.4, 1593.7, 1350.8, 1164.3 cm–1; 1H-NMR (400 MHz, CDCl3) δ 7.77 (d, J = 8.4 Hz, 2H), 7.34–7.40 (m, 5H), 7.23–7.25 (m, 1H), 7.12 (d, J = 1.2 Hz, 2H), 5.45 (dd, J = 8.2, 3.4 Hz, 1H), 3.76 (ddd, J = 8.4, 4.4, 2.0 Hz, 1H), 3.64 (dd, J = 8.8, 4.0 Hz, 1H), 3.52 (dd, J = 8.8, 6.4 Hz, 1H), 3.34 (dd, J = 15.8, 3.4 Hz, 1H), 2.99 (dd, J = 15.8, 8.2 Hz, 1H), 2.44 (s, 3H), 1.39 (d, J = 6.4 Hz, 3H); 13C-NMR (100 MHz, CDCl3) δ 168.0, 150.5, 144.4, 133.6, 130.1, 129.4, 129.1, 127.9, 126.0, 121.6, 88.9, 72.0, 55.2, 42.5, 21.6, 21.0; HRMS (ESI+) calcd for [C19H21NO5S]+: m/z 376.1213, found 376.1204.
1-[(2S,4S)-4-Methyl-3-tosyloxazolidin-2-yl]propan-2-one (4e). 68% yield; yellow oil; IR (CH2Cl2) νmax 2980.2, 1715.8, 1598.2, 1348.8, 1164.6 cm–1; 1H-NMR (400 MHz, CDCl3) δ 7.66 (d, J = 8.4 Hz, 2H), 7.28 (d, J = 8.0 Hz, 2H), 5.23 (dd, J = 8.4, 2.4 Hz, 1H), 3.65 (ddd, J = 7.8, 4.6, 1.8 Hz, 1H), 3.47 (dd, J = 8.8, 3.6 Hz, 1H), 3.32 (dd, J = 9.0, 6.2 Hz, 1H), 3.11 (dd, J = 16.6, 2.6 Hz, 1H), 2.84 (dd, J = 16.4. 8.4 Hz, 1H), 2.36 (s, 3H), 2.14 (s, 3H), 1.26 (d, J = 6.8 Hz, 3H); 13C-NMR (100 MHz, CDCl3) δ 205.1, 144.3, 133.5, 130.0, 127.8, 126.9, 88.4, 71.8, 54.9, 50.6, 30.8, 21.5, 21.0; HRMS (ESI+) calcd for [C14H19NO4S]+: m/z 298.1108, found 298.1128.
2-[(2S,4S)-4-Methyl-3-tosyloxazolidin-2-yl]-1-phenylethanone (4f). 57% yield; white solid; IR (CH2Cl2) νmax 3062.3, 2980.2, 1686.7, 1597.3, 1348.9, 1164.5 cm–1; 1H-NMR (400 MHz, CDCl3) δ 7.97 (d, J = 7.2 Hz, 2H), 7.73 (d, J = 8.0 Hz, 2H), 7.53–7.74 (m, 1H), 7.45 (t, J = 7.6 Hz, 2H), 7.31 (d, J = 8.0 Hz, 2H), 5.50 (dd, J = 8.8, 2.0 Hz, 1H), 3.71–3.75 (m, 2H), 3.55 (dd, J = 8.8, 3.6 Hz, 1H), 3.37–3.45 (m, 2H), 2.39 (s, 3H), 1.35 (d, J = 6.4 Hz, 3H); 13C-NMR (100 MHz, CDCl3) δ 196.6, 144.4, 136.6, 133.5, 130.1, 130.0, 129.6, 128.7, 128.3, 127.9, 89.0, 71.9, 55.0, 46.3, 21.6, 21.1; HRMS (ESI+) calcd for [C19H21NO4S]+: m/z 360.1264, found 360.1260.
1-(3,4-Dichlorophenyl)-2-[(2S,4S)-4-methyl-3-tosyloxazolidin-2-yl]ethanone (4g). 41% yield; brown oil; IR (CH2Cl2) νmax 3065.8, 2980.5, 1692.7, 1584.3, 1349.3, 1164.8 cm–1; 1H-NMR (400 MHz, CDCl3) δ 8.03 (d, J = 2.0 Hz, 1H), 7.79 (dd, J = 8.4, 2.0 Hz, 1H), 7.71 (d, J = 8.4 Hz, 2H), 7.32 (d, J = 8.0 Hz, 2H), 5.42 (dd, J = 8.4, 2.0 Hz, 1H), 3.67–3.74 (m, 2H), 3.55 (dd, J = 9.0, 3.4 Hz, 1H), 3.32–3.40 (m, 2H), 2.40 (s, 3H), 1.34 (d, J = 6.4 Hz, 3H); 13C-NMR (100 MHz, CDCl3) δ 194.4, 144.5, 138.4, 137.0, 134.0, 133.4, 131.1, 130.8, 130.0, 128.3, 127.4, 88.8, 72.0, 55.0, 46.3, 21.6, 21.1; HRMS (ESI+) calcd for [C19H19Cl2NO4S]+: m/z 428.0485, found 428.0476.
1-(3,4-Dimethoxyphenyl)-2-[(2S,4S)-4-methyl-3-tosyloxazolidin-2-yl]ethanone (4h). 90% yield; yellow oil; IR (CH2Cl2) νmax 3064.1, 2974.2, 1672.7, 1595.4, 1346.4, 1163.4 cm–1; 1H-NMR (400 MHz, CDCl3) δ 7.64 (d, J = 8.0 Hz, 2H), 7.53 (dd, J = 8.4, 2.0 Hz, 1H), 7.43 (d, J = 2.0 Hz, 1H), 7.22 (d, J = 8.0 Hz, 2H), 6.81 (d, J = 8.4 Hz, 1H), 5.40 (dd, J = 8.8, 2.0 Hz, 1H), 3.78–3.81 (m, 7H), 3.62 (ddd, J = 12.5, 6.1, 3.3 Hz, 1H), 3.56 (d, J = 2.0 Hz, 1H), 3.47 (dd, J = 8.8, 3.6 Hz, 1H), 3.26–3.32 (m, 2H), 2.29 (s, 3H), 1.25 (d, J = 6.4 Hz, 3H); 13C-NMR (100 MHz, CDCl3) δ 195.0, 153.6, 149.0, 144.3, 133.4, 130.0, 127.8, 110.2, 89.3, 71.8, 56.0, 55.0, 45.8, 21.4, 20.9; HRMS (ESI+) calcd for [C21H25NO6S]+: m/z 420.1475, found 420.1464.
1-(4-Fluorophenyl)-2-[(2S,4S)-4-Methyl-3-tosyloxazolidin-2-yl]ethanone (4i). 51% yield; white solid; IR (CH2Cl2) νmax 3069.4, 2981.0, 1686.4, 1597.3, 1349.2, 1164.7 cm–1; 1H-NMR (400 MHz, CDCl3) δ 8.00 (q, J = 1.1 Hz, 2H), 7.72 (d, J = 8.4 Hz, 2H), 7.31 (d, J = 8.0 Hz, 2H), 7.12 (t, J = 8.8 Hz, 2H), 5.46 (dd, J = 8.8, 2.0 Hz, 1H), 3.67–3.74 (m, 2H), 3.55 (dd, J = 8.8, 3.6 Hz, 1H), 3.35–3.41 (m, 2H), 2.39 (s, 3H), 1.34 (d, J = 6.4 Hz, 3H); 13C-NMR (100 MHz, CDCl3) δ 195.0, 167.2, 164.7, 144.4, 133.4, 133.1, 131.0, 130.1, 127.9, 115.9, 89.0, 71.9, 55.0, 46.2, 21.5, 21.1; HRMS (ESI+) calcd for [C19H20FNO4S]+: m/z 378.1170, found 378.1170.
2-[(2S,4S)-4-Methyl-3-tosyloxazolidin-2-yl]-1-(naphth-1-yl)ethanone (4j). 84% yield; brown oil; IR (CH2Cl2) νmax 3051.4, 2980.3, 1678.6, 1596.0, 1348.9, 1164.0 cm–1; 1H-NMR (400 MHz, CDCl3) δ 8.73 (d, J = 8.4 Hz, 1H), 7.97 (d, J = 7.6 Hz, 2H), 7.84 (d, J = 8.0 Hz, 1H), 7.75 (d, J = 8.0 Hz, 2H), 7.47–7.59 (m, 3H), 7.28 (d, J = 8.0 Hz, 2H), 5.59 (dd, J = 8.6, 2.2 Hz, 1H), 3.89 (dd, J = 16.4, 2.4 Hz, 1H), 3.75 (ddd, J = 8.1, 4.5, 1.9 Hz, 1H), 3.56 (dd, J = 9.0, 3.4 Hz, 1H), 3.50 (dd, J = 16.8, 8.8 Hz, 1H), 3.39 (dd, J = 9.0, 6.2 Hz, 1H), 2.35 (s, 3H), 1.36 (d, J = 6.8 Hz, 3H); 13C-NMR (100 MHz, CDCl3) δ 200.2, 144.4, 134.9, 134.0, 133.5, 133.3, 130.2, 130.0, 128.6, 128.1, 126.6, 126.0, 124.5, 89.4, 71.9, 55.1, 49.4, 21.5, 21.1; HRMS (ESI+) calcd for [C23H23NO4S]+: m/z 410.1421, found 410.1421.
2-[(2S,4S)-4-Methyl-3-tosyloxazolidin-2-yl]-1-(thien-2-yl)ethanone (4k). 49% yield; brown solid; IR (CH2Cl2) νmax 3102.9, 2980.4, 1658.8, 1597.7, 1348.9, 1164.0 cm–1; 1H-NMR (400 MHz, CDCl3) δ 7.78 (dd, J = 3.8, 1.0 Hz, 1H), 7.72 (d, J = 8.0 Hz, 2H), 7.65 (dd, J = 5.0, 1.0 Hz, 1H), 7.32 (d, J = 8.0 Hz, 2H), 7.13 (dd, J = 4.8, 4.0 Hz, 1H), 5.45 (dd, J = 7.6, 3.2 Hz, 1H), 3.72 (ddd, J = 8.0, 4.4, 1.8 Hz, 1H), 3.63 (dd, J = 16.0, 2.0 Hz, 1H), 3.56 (dd, J = 8.8, 3.6 Hz, 1H), 3.32–3.41 (m, 2H), 2.40 (s, 3H), 1.34 (d, J = 6.4 Hz, 3H); 13C-NMR (100 MHz, CDCl3) δ 189.1, 144.4, 144.0, 134.4, 133.4, 132.9, 130.0, 128.4, 127.9, 89.0, 71.9, 55.0, 46.9, 21.6, 21.0; HRMS (ESI+) calcd for [C17H19NO4S2]+: m/z 366.0828, found 366.0822.
Methyl 2-[(2S,4R)-4-benzyl-3-tosyloxazolidin-2-yl]acetate (5a). 66% yield; white solid; IR (CH2Cl2) νmax 3028.3, 2952.2, 1740.7, 1597.9, 1351.7, 1163.9 cm–1; 1H-NMR (400 MHz, CDCl3) δ 7.77 (d, J = 8.4 Hz, 2H), 7.18–7.34 (m, 7H), 5.33 (dd, J = 8.8, 2.8 Hz, 1H), 3.83 (ddd, J = 12.8, 6.4, 3.2 Hz, 1H), 3.72 (dd, J = 9.2, 3.6 Hz, 1H), 3.69 (s, 3H), 3.22 (dd, J = 9.2, 6.4 Hz, 1H), 3.13 (dd, J = 13.6, 3.6 Hz, 1H), 3.06 (dd, J = 15.8, 3.0 Hz, 1H), 2.84 (dd, J = 13.2, 10.0 Hz, 1H), 2.60 (dd, J = 15.8, 8.6 Hz, 1H), 2.40 (s, 3H); 13C-NMR (100 MHz, CDCl3) δ 169.9, 144.5, 137.0, 133.6, 130.1, 129.6, 128.7, 127.9, 126.9, 89.0, 69.1, 60.5, 51.9, 41.8, 40.9, 21.6; HRMS (ESI+) calcd for [C20H23NO5S]+: m/z 390.1370, found 390.1364.
Ethyl 2-[(2R,4S)-4-benzyl-3-tosyloxazolidin-2-yl]acetate (5b). 81% yield; white solid; IR (CH2Cl2) νmax 3028.3, 2983.2, 1736.0, 1597.9, 1352.0, 1164.1 cm–1; 1H-NMR (400 MHz, CDCl3) δ 7.75 (dd, J = 8.4 Hz, 2H), 7.30 (d, J = 8.4 Hz, 2H), 7.26 (d, J = 7.6 Hz, 2H), 7.18 (d, J = 8.0 Hz, 3H), 5.33 (dd, J = 8.8, 2.8 Hz, 1H), 4.14 (q, J = 7.2 Hz, 2H), 3.82 (ddd, J = 13.0, 6.6, 3.2 Hz, 1H), 3.70 (dd, J = 9.2, 3.2 Hz, 1H), 3.20 (dd, J = 9.2, 6.0 Hz, 1H), 3.13 (dd, J = 13.4, 3.8 Hz, 1H), 3.05 (dd, J = 15.8, 3.0 Hz, 1H), 2.83 (dd, J = 13.4, 9.8 Hz, 1H), 2.37 (s, 3H), 1.24 (t, J = 7.2 Hz, 3H); 13C-NMR (100 MHz, CDCl3) δ 169.5, 144.5, 137.1, 133.6, 130.1, 129.6, 128.7, 127.9, 126.9, 89.1, 69.1, 60.7, 60.4, 42.0, 41.0, 21.5, 14.2; HRMS (ESI+) calcd for [C21H25NO5S]+: m/z 404.1526, found 404.1528.
Benzyl 2-[(2S,4R)-4-benzyl-3-tosyloxazolidin-2-yl]acetate (5c). 76% yield; yellow oil; IR (CH2Cl2) νmax 3063.3, 3030.3, 2948.4, 1737.7, 1597.8, 1352.0, 1164.0 cm–1; 1H-NMR (400 MHz, CDCl3) δ 7.81 (d, J = 8.0 Hz, 2H), 7.23–7.42 (m, 12H), 5.44 (dd, J = 8.4, 3.2 Hz, 1H), 5.20 (s, 2H), 3.89 (ddd, J = 12.9, 6.5, 3.1 Hz, 1H), 3.78 (dd, J = 8.4, 5.2 Hz, 1H), 3.27 (dd, J = 9.2, 6.4 Hz, 1H), 3.16–3.21 (m, 2H), 2.88 (dd, J = 13.6, 10.0 Hz, 1H), 2.73 (dd, J = 16.0, 8.4 Hz, 1H), 2.43 (s, 3H); 13C-NMR (100 MHz, CDCl3) δ 169.4, 144.6, 137.1, 135.8, 133.7, 130.2, 130.1, 129.6, 128.8, 128.7, 128.5, 128.3, 128.0, 127.0, 89.2, 69.2, 66.7, 60.6, 42.1, 41.0, 21.6; HRMS (ESI+) calcd for [C26H27NO5S]+: m/z 466.1683, found 466.1687.
Phenyl 2-[(2S,4R)-4-benzyl-3-tosyloxazolidin-2-yl]acetate (5d). 5% yield; yellow oil; IR (CH2Cl2) νmax 3028.5, 2924.3, 1712.3, 1589.8, 1325.3, 1362.2 cm–1; 1H-NMR (400 MHz, CDCl3) δ 7.80 (d, J = 8.4 Hz, 2H), 7.05–7.42 (m, 12H), 5.42 (dd, J = 8.0, 3.2 Hz, 1H), 3.86 (ddd, J = 13.1, 6.3, 3.3 Hz, 1H), 3.79 (dd, J = 9.2, 3.2 Hz, 1H), 3.33 (dd, J = 16.0, 3.2 Hz, 1H), 3.27 (dd, J = 9.0, 6.2 Hz, 1H), 3.20 (dd, J = 13.6, 3.6 Hz, 1H), 2.82–2.92 (m, 3H), 2.43 (s, 3H); 13C-NMR (100 MHz, CDCl3) δ 167.0, 159.8, 155.7, 143.4, 137.5, 136.3, 129.7, 127.0, 128.0, 101.1, 64.5, 54.1, 38.8, 21.5; HRMS (ESI+) calcd for [C25H25NO5S]+: m/z 452.1526, found 452.1515.
1-[(2S,4S)-4-Benzyl-3-tosyloxazolidin-2-yl]propan-2-one (5e). 45% yield; yellow oil; IR (CH2Cl2) νmax 3062.3, 2924.8, 1716.7, 1598.0, 1349.8, 1163.6 cm–1; 1H-NMR (400 MHz, CDCl3) δ 7.74 (d, J = 8.4 Hz, 2H), 7.32 (d, J = 8.0 Hz, 2H), 7.29 (d, J = 7.6 Hz, 2H), 7.19–7.22 (m, 3H), 5.27 (dd, J = 8.4, 2.4 Hz, 1H), 3.80 (ddd, J = 9.4, 6.2, 3.2 Hz, 1H), 3.69 (dd, J = 9.2, 2.8 Hz, 1H), 3.10–3.17 (m, 3H), 2.83 (dd, J = 13.6, 10.0 Hz, 1H), 2.72 (dd, J = 16.8, 8.4 Hz, 1H), 2.40 (s, 3H), 2.13 (s, 3H); 13C- NMR (100 MHz, CDCl3) δ 205.1, 144.5, 137.1, 133.5, 13071, 129.7, 128.7, 127.9, 126.9, 88.6, 69.0, 60.3, 50.2, 41.0, 30.8, 21.6; HRMS (ESI+) calcd for [C20H23NO4S]+: m/z 374.1421, found 374.1413.
2-[(2S,4R)-4-Benzyl-3-tosyloxazolidin-2-yl]-1-phenylethanone (5f). 71% yield; white solid; IR (CH2Cl2) νmax 3060.0, 3027.9, 2924.2, 1687.4, 1597.2, 1349.6, 1163.3 cm–1; 1H-NMR (400 MHz, CDCl3) δ 7.92 (d, J = 7.2 Hz, 2H), 7.80 (d, J = 8.4 Hz, 2H), 7.24–7.58 (m, 9H), 5.55 (dd, J = 8.8, 2.0 Hz, 1H), 3.89 (ddd, J = 9.4, 6.2, 3.4 Hz, 1H), 3.75 (dd, J = 9.6, 3.2 Hz, 1H), 3.63 (dd, J = 16.8, 2.0 Hz, 1H), 3.13–3.28 (m, 3H), 2.97 (dd, J = 13.4, 9.4 Hz, 1H), 2.40 (s, 3H); 13C-NMR (100 MHz, CDCl3) δ 196.6, 144.5, 137.1 ,136.6, 133.5, 130.1, 130.0, 129.1, 128.7, 128.3, 128.0, 127.0, 89.2, 69.0, 60.2, 45.6, 40.8, 21.6; HRMS (ESI+) calcd for [C25H25NO4S]+: m/z 436.1577, found 436.1576.
2-[(2R,4R)-4-Benzyl-3-tosyloxazolidin-2-yl]-1-(3,4-dichlorophenyl)ethanone (5g). 30% yield; white solid; IR (CH2Cl2) νmax 3063.5, 3028.4, 2924.0, 1691.4, 1597.7, 1350.47, 1164.0 cm–1; 1H-NMR (400 MHz, CDCl3) δ 7.94 (d, J = 2.0 Hz, 1H), 7.78 (d, J = 8.4 Hz, 2H), 7.72 (dd, J = 8.4, 2.0 Hz, 1H), 7.54 (d, J = 8.4 Hz, 2H), 7.25–7.37 (m, 8H), 5.46 (dd, J = 8.6, 2.2 Hz, 1H), 3.87 (ddd, J = 9.1, 6.1, 3.1 Hz, 1H), 3.76 (dd, J = 9.2, 3.2 Hz, 1H), 3.51 (dd, J = 16.8, 2.0 Hz, 1H), 3.28 (dd, J = 9.2, 6.4 Hz, 1H), 2.96–3.12 (m, 3H), 2.43 (s, 3H); 13C-NMR (100 MHz, CDCl3) δ 194.4, 144.6, 138.0, 136.9, 136.0, 133.4, 133.3, 130.8, 130.3, 130.1, 128.7, 127.9, 127.3, 127.0, 88.9, 69.0, 60.0, 45.5, 40.6, 21.6; HRMS (ESI+) calcd for [C25H23Cl2NO4S]+: m/z 504.0798, found 504.0802.
2-[(2R,4R)-4-Benzyl-3-tosyloxazolidin-2-yl]-1-(3,4-dimethoxyphenyl)ethanone (5h). 98% yield; yellow oil; IR (CH2Cl2) νmax 3062.0, 3027.3, 2936.2, 1672.8, 1595.7, 1347.3, 1163.2 cm–1; 1H-NMR (400 MHz, CDCl3) δ 7.73 (d, J = 8.0 Hz, 2H), 7.45–7.54 (m, 2H), 7.24 (t, J = 7.2 Hz, 2H), 7.17 (d, J = 14.0 Hz, 2H), 6.90–6.93 (m, 1H), 6.84 (d, J = 8.4 Hz, 1H), 5.47 (dd, J = 8.8, 2.0 Hz, 1H), 3.85 (s, 3H), 3.83 (s, 3H), 3.68 (dd, J = 9.0, 3.4 Hz, 1H), 3.52 (dd, J = 16.4, 1.6 Hz, 1H), 3.19 (dd, J = 9.2, 6.4 Hz, 1H), 3.04–3.13 (m, 1H), 2.88 (dd, J = 13.4, 9.4 Hz, 1H), 2.31 (s, 3H); 13C-NMR (100 MHz, CDCl3) δ 195.1, 153.6, 149.0, 144.4, 143.0, 137.5, 137.3, 137.0, 133.4, 130.1, 130.0, 129.9, 129.8, 126.8, 110.1, 89.4, 68.9, 56.8, 56.1, 55.9, 45.1, 40.6, 21.5, 21.0; HRMS (ESI+) calcd for [C27H29NO6S]+: m/z 496.1788, found 496.1779.
2-[(2R,4R)-4-Benzyl-3-tosyloxazolidin-2-yl]-1-(4-fluorophenyl)ethanone (5i). 51% yield; yellow solid; IR (CH2Cl2) νmax 3063.5, 3028.6, 2924.9, 1686.4, 1597.2, 1350.0, 1163.9 cm–1; 1H-NMR (400 MHz, CDCl3) δ 7.93 (dd, J = 8.8, 5.6 Hz, 2H), 7.79 (d, J = 8.0 Hz, 2H), 7.10–7.34 (m, 9H), 5.50 (dd, J = 8.8, 2.0 Hz, 1H), 3.87 (ddd, J = 9.3, 6.3, 3.1 Hz, 1H), 3.75 (dd, J = 9.2, 3.2 Hz, 1H), 3.52 (dd, J = 16.8, 2.0 Hz, 1H), 3.25 (dd, J = 9.2, 6.0 Hz, 1H), 2.98–3.18 (m, 2H), 2.95 (dd, J = 13.6, 9.6 Hz, 1H), 2.40 (s, 3H); 13C-NMR (100 MHz, CDCl3) δ 195.0, 167.2, 164.7, 144.5, 137.0, 133.5, 133.1, 131.1, 131.0, 130.2, 130.0, 128.7, 128.0, 127.0, 115.8, 89.2, 69.0, 60.2, 45.5, 40.8, 21.6; HRMS (ESI+) calcd for [C25H24FNO4S]+: m/z 454.1483, found 454.1489.
2-[(2R,4R)-4-Benzyl-3-tosyloxazolidin-2-yl]-1-(naphth-1-yl)ethanone (5j). 96% yield; yellow oil; IR (CH2Cl2) νmax 3060.6, 3028.6, 2924.4, 1678.7, 1596.3, 1349.6, 1163.4 cm–1; 1H-NMR (400 MHz, CDCl3) δ 8.82 (d, J = 8.4 Hz, 1H), 7.99 (d, J = 8.0 Hz, 1H), 7.84–7.90 (m, 4H), 7.50–7.62 (m, 3H), 7.22–7.35 (m, 7H), 5.66 (dd, J = 8.6, 2.2 Hz, 1H), 3.94 (ddd, J = 9.3, 6.3, 3.1 Hz, 1H), 3.78–3.85 (m, 2H), 3.34 (dd, J = 16.8, 8.8 Hz, 1H), 3.28 (dd, J = 9.2, 6.0 Hz, 1H), 3.18 (dd, J = 13.4, 3.4 Hz, 1H), 2.98 (dd, J = 13.6, 9.2 Hz, 1H), 2.36 (s, 3H); 13C-NMR (100 MHz, CDCl3) δ 200.1, 144.5, 137.1, 134.9, 134.0, 133.6, 133.4, 130.3, 130.2, 130.0, 128.9, 128.7, 128.6, 128.2, 128.0, 127.0, 126.6, 126.0, 127.5, 89.7, 69.1, 60.4, 48.8, 40.9, 21.6; HRMS (ESI+) calcd for [C29H27NO4S]+: m/z 486.1734, found 486.1729.
2-[(2R,4R)-4-Benzyl-3-tosyloxazolidin-2-yl]-1-(thien-2-yl)ethanone (5k). 41% yield; brown solid; IR (CH2Cl2) νmax 3105.0, 3028.7, 2918.5, 1660.9, 1597.4, 1350.3, 1163.1 cm–1; 1H-NMR (400 MHz, CDCl3) δ 7.79 (d, J = 8.0 Hz, 2H), 7.69 (dd, J = 3.8, 1.0 Hz, 1H), 7.66 (dd, J = 5.0, 1.0 Hz, 1H), 7.33 (t, J = 7.2 Hz, 4H), 7.25 (d, J = 6.8 Hz, 3H), 7.14 (t, J = 2.6 Hz, 1H), 5.47 (dd, J = 8.6, 2.2 Hz, 1H), 3.86 (ddd, J = 9.4, 6.2, 3.2 Hz, 1H), 3.76 (dd, J = 9.2, 3.2 Hz, 1H), 3.54 (dd, J = 16.2, 2.2 Hz, 1H), 3.25 (dd, J = 9.2, 6.4 Hz, 1H), 3.09–3.15 (m, 2H), 2.94 (dd, J = 13.6, 9.6 Hz, 1H), 2.42 (s, 3H); 13C- NMR (100 MHz, CDCl3) δ 189.2, 144.6, 144.1, 137.1, 134.5, 134.4 ,133.5, 132.9, 130.2, 130.0, 128.7, 128.3, 128.0, 127.0, 89.2, 69.0, 60.2, 46.2, 40.7, 21.6; HRMS (ESI+) calcd for [C23H23NO4S2]+: m/z 442.1141, found 442.1119.
Methyl 2-[(2S,4R)-4-(hydroxymethyl)-3-tosyloxazolidin-2-yl]acetate (6a). 38% yield; yellow oil; IR (CH2Cl2) νmax 3532.4, 2953.5, 1738.3. 1597.5. 1349.3. 1164.0 cm–1; 1H-NMR (400 MHz, CDCl3) δ 7.73 (d, J = 8.4 Hz, 2H), 7.34 (d, J = 8.4 Hz, 2H), 5.31 (dd, J = 8.2, 3.4 Hz, 1H), 3.87 (dd, J = 9.0, 3.4 Hz, 1H), 3.63–3.69 (m, 6H), 3.44 (dd, J = 9.0, 6.2 Hz, 1H), 3.03 (dd, J = 15.6, 3.6 Hz, 1H), 2.75 (dd, J = 16.0, 8.0 Hz, 1H), 2.41 (s, 3H); 13C-NMR (100 MHz, CDCl3) δ 170.0, 144.8, 133.0, 130.2, 128.0, 127.0, 89.1, 67.6, 63.1, 60.2, 52.0, 41.3, 21.6; HRMS (ESI+) calcd for [C14H19NO6S]+: m/z 330.1006, found 330.0995.
Ethyl 2-[(2S,4R)-4-(hydroxymethyl)-3-tosyloxazolidin-2-yl]acetate (6b). 50% yield; brown oil; IR (CH2Cl2) νmax 3531.9, 2982.6, 1732.1, 1597.6, 1350.5, 1164.6 cm–1; 1H-NMR (400 MHz, CDCl3) δ 7.73 (d, J = 8.4 Hz, 2H), 7.33 (dd, J = 8.0 Hz, 2H), 5.31 (dd, J = 8.2, 3.4 Hz, 1H), 4.14 (q, J = 7.2 Hz, 2H), 3.87 (dd, J = 9.4, 3.4 Hz, 1H), 3.63–3.70 (m, 3H), 3.44 (dd, J = 9.0, 6.2 Hz, 1H), 3.01 (dd, J = 15.8, 3.4 Hz, 2H), 2.73 (dd, J = 15.8, 8.2 Hz, 1H), 2.37–2.41 (m, 4H), 1.24 (t, J = 7.2 Hz, 3H); 13C- NMR (100 MHz, CDCl3) δ 169.6, 144.8, 133.1, 130.1, 128.0, 89.1, 67.6, 63.2, 61.0, 60.2, 41.5, 21.6, 14.1; HRMS (ESI+) calcd for [C15H21NO6S]+: m/z 344.1162, found 344.1186.
Benzyl 2-[(2S,4R)-4-(hydroxymethyl)-3-tosyloxazolidin-2-yl]acetate (6c). 37% yield; brown oil; IR (CH2Cl2) νmax 3532.5, 3064.1, 2949.6, 1736.5, 1597.4, 1350.1, 1164.3 cm–1; 1H-NMR (400 MHz, CDCl3) δ 7.75 (d, J = 8.0 Hz, 2H), 7.33–7.37 (m, 7H), 5.38 (dd, J = 8.0, 3.6 Hz, 1H), 5.16 (s, 2H), 3.89 (dd, J = 9.2, 3.6 Hz, 1H), 3.64–3.73 (m, 3H), 3.46 (dd, J = 9.2, 6.4 Hz, 1H), 3.10 (dd, J = 15.6, 3.6 Hz, 1H), 2.83 (dd, J = 15.6, 8.0 Hz, 1H), 2.42 (s, 3H); 13C-NMR (100 MHz, CDCl3) δ 169.5, 144.8, 141.0, 135.5, 133.1, 130.2, 128.6, 128.3, 128.0, 127.0, 89.1, 67.6, 66.8, 65.1, 63.2, 60.2, 41.5, 21.6; HRMS (ESI+) calcd for [C20H23NO6S]+: m/z 406.1319, found 406.1327.
Phenyl 2-[(2S,4R)-4-(hydroxymethyl)-3-tosyloxazolidin-2-yl]acetate (6d). 8% yield; yellow oil; IR (CH2Cl2) νmax 3515.0, 3064.8, 2526.4, 1755.0, 1594.6, 1324.6, 1163.1 cm–1; 1H-NMR (400 MHz, CDCl3) δ 7.77 (d, J = 3.2 Hz, 2H), 7.74 (d, J = 4.4 Hz, 2H), 7.05–7.15 (m, 5H), 5.48 (dd, J = 7.6, 4.0 Hz, 1H), 3.95 (dd, J = 9.0, 3.8 Hz, 1H), 3.72–3.76 (m, 2H), 3.46–3.57 (m, 3H), 3.31 (dd, J = 15.4, 3.8 Hz, 1H), 3.03 (dd, J = 15.6, 7.6 Hz, 1H), 2.45 (s, 3H); 13C-NMR (100 MHz, CDCl3) δ 168.1, 150.4, 144.9, 143.7, 133.0, 130.2, 130.1, 129.8, 129.4, 128.0, 127.1, 121.6, 118.0, 100.8, 89.1, 67.7, 63.3, 62.4, 54.1, 41.6, 21.6; HRMS (ESI+) calcd for [C19H21NO6S]+: m/z 392.1162, found 392.1187.
1-[(2S,4R)-4-(Hydroxymethyl)-3-tosyloxazolidin-2-yl]propan-2-one (6e). 29% yield; yellow oil; IR (CH2Cl2) νmax 3516.2, 3060.0, 2953.8, 1715.3, 1597.3, 1348.3, 1163.9 cm–1; 1H NMR (400 MHz, CDCl3) δ 7.72 (d, J = 8.0 Hz, 2H), 7.34 (d, J = 8.0 Hz, 2H), 5.28 (dd, J = 8.0, 2.8 Hz, 1H), 3.84 (dd, J = 10.4, 2.8 Hz, 1H), 3.67 (s, 3H), 3.35–3.39 (m, 1H), 3.15 (dd, J = 16.8, 2.8 Hz, 1H), 2.92 (dd, J = 16.8, 8.0 Hz, 2H), 2.42 (s, 3H), 2.19 (s, 3H); 13C NMR (100 MHz, CDCl3) δ 205.3, 144.8, 132.9, 130.2, 128.0, 88.7, 67.7, 63.5, 60.0, 49.8, 30.9, 21.6; HRMS (ESI+) calcd for [C14H19NO5S]+: m/z 314.1057, found 314.1050.
2-[(2S,4R)-4-(Hydroxymethyl)-3-tosyloxazolidin-2-yl]-1-phenylethanone (6f). 23% yield; brown solid; IR (CH2Cl2) νmax 3515.4, 3061.5, 2933.4, 1687.2, 1597.1, 1347.7, 1163.3 cm–1; 1H-NMR (400 MHz, CDCl3) δ 7.96 (d, J = 8.4 Hz, 2H), 7.75 (d, J = 8.4 Hz, 2H), 7.54–7.58 (m, 1H), 7.45 (t, J = 7.6 Hz, 2H), 7.34 (d, J = 8.0 Hz, 2H), 5.53 (dd, J = 8.4, 2.4 Hz, 1H), 3.88 (dd, J = 8.6, 2.2 Hz, 1H), 3.68–3.72 (m, 4H), 3.47 (dd, J = 16.8, 8.4 Hz, 1H), 3.39–3.42 (m, 1H), 2.41 (s, 3H); 13C-NMR (100 MHz, CDCl3) δ 196.7, 144.8, 136.5, 133.6, 133.0, 130.2, 130.0, 128.7, 128.3, 128.0, 89.3, 67.8, 63.5, 60.1, 45.5, 21.6; HRMS (ESI+) calcd for [C19H21NO5S]+: m/z 376.1213, found 376.1187.
1-(3,4-Dichlorophenyl)-2-[(2S,4R)-4-(hydroxymethyl)-3-tosyloxazolidin-2-yl]ethanone (6g). 12% yield; brown oil; IR (CH2Cl2) νmax 3513.6, 3064.1, 2925.2, 1691.4, 1584.1, 1333.8, 1162.5 cm–1; 1H- NMR (400 MHz, CDCl3) δ 8.05 (d, J = 2.0 Hz, 1H), 7.80 (d, J = 7.6 Hz, 2H), 7.37 (d, J = 8.0 Hz, 2H), 7.28 (d, J = 7.6 Hz, 2H), 5.48 (dd, J = 8.2, 2.6 Hz, 1H), 3.88 (dd, J = 8.6, 2.2 Hz, 1H), 3.66–3.77 (m, 7H), 3.39–3.45 (m, 2H), 2.45 (s, 3H), 2.40–2.42 (m, 4H); 13C-NMR (100 MHz, CDCl3) δ 194.4, 145.0, 144.2, 138.2, 136.1, 133.5, 132.8, 131.0, 130.9, 128.0, 127.3, 127.2, 126.9, 126.4, 89.1, 60.1, 53.4, 21.6; HRMS (ESI+) calcd for [C19H19Cl2NO5S]+: m/z 444.0434, found 444.0388.
1-(3,4-Dimethoxyphenyl)-2-[(2S,4R)-4-(hydroxymethyl)-3-tosyloxazolidin-2-yl]ethanone (6h). 38% yield; yellow oil; IR (CH2Cl2) νmax 3268.9, 3060.0, 2966.1, 1673.8, 1595.8, 1334.0, 1149.5 cm–1; 1H- NMR (400 MHz, CDCl3) δ 7.73 (d, J = 8.4 Hz, 2H), 7.49 (dd, J = 8.4, 2.0 Hz, 1H), 7.41 (d, J = 2.0 Hz, 1H), 7.22 (d, J = 8.0 Hz, 2H), 6.81 (d, J = 8.4 Hz, 1H), 6.07 (d, J = 9.6 Hz, 1H), 5.13 (t, J = 5.0 Hz, 1H), 3.88 (s, 3H), 3.73–3.84 (m, 6H), 3.27 (d, J = 9.6 Hz, 1H), 3.22 (d, J = 4.8 Hz, 2H), 2.34 (s, 3H); 13C-NMR (100 MHz, CDCl3) δ 194.6, 194.5, 153.6, 149.0, 148.9, 143.7, 143.5, 138.1, 137.7, 130.0, 129.8, 127.0, 126.8, 123.4, 110.1, 100.0, 70.5, 56.0, 47.8, 45.3, 43.1, 42.8, 21.5; HRMS (ESI+) calcd for [C21H25NO7S]+: m/z 436.1425, found 436.1418.
1-(4-Fluorophenyl)-2-[(2S,4R)-4-(hydroxymethyl)-3-tosyloxazolidin-2-yl]ethanone (6i). 23% yield; brown oil; IR (CH2Cl2) νmax 3515.7, 3064.1, 2925.2, 1687.0, 1597.5, 1346.7, 1163.5 cm–1; 1H-NMR (400 MHz, CDCl3) δ 8.00 (dd, J = 8.8, 5.6 Hz, 2H), 7.75 (d, J = 8.4 Hz, 2H), 7.35 (d, J = 8.0 Hz, 2H), 7.12 (t, J = 8.6 Hz, 2H), 5.51 (dd, J = 8.4, 2.4 Hz, 1H), 3.88 (dd, J = 8.4, 2.0 Hz, 1H), 3.65–3.74 (m, 5H), 3.39–3.48 (m, 2H), 2.43 (s, 3H), 2.38–2.41 (m, 1H); 13C-NMR (100 MHz, CDCl3) δ 195.1, 144.9, 132.9, 132.4, 132.3, 131.1, 131.0, 130.2, 129.1, 128.0, 89.3, 67.8, 63.4, 60.1, 45.4, 22.6, 21.6; HRMS (ESI+) calcd for [C19H20FNO5S]+: m/z 394.1119, found 394.1100.
2-[(2S,4R)-4-(Hydroxymethyl)-3-tosyloxazolidin-2-yl]-1-(naphth-1-yl)ethanone (6j). 24% yield; brown oil; IR (CH2Cl2) νmax 3515.8, 3052.0, 2957.9, 1678.1, 1509.0, 1346.9, 1163.1 cm–1; 1H-NMR (400 MHz, CDCl3) δ 8.70 (d, J = 8.0 Hz, 1H), 7.98 (dd, J = 9.0, 4.6 Hz, 2H), 7.77 (d, J = 8.4 Hz, 2H), 7.48–7.60 (m, 4H), 7.33 (d, J = 8.0 Hz, 2H), 5.58 (dd, J = 8.4, 2.8 Hz, 1H), 3.86–3.91 (m, 2H), 3.65–3.78 (m, 4H), 3.52 (dd, J = 16.4, 8.4 Hz, 1H), 3.42 (dd, J = 9.0, 6.2 Hz, 1H), 2.41 (s, 3H); 13C-NMR (100 MHz, CDCl3) δ 200.2, 144.8, 134.9, 134.0, 133.8, 133.4, 133.0, 130.2, 128.7, 128.6, 128.5, 125.9, 89.8, 76.8, 60.4, 48.7, 21.5, 21.1; HRMS (ESI+) calcd for [C23H23NO5S]+: m/z 426.1370, found 426.1365.
2-[(2R,4R)-4-(Hydroxymethyl)-3-tosyloxazolidin-2-yl]-1-(thien-2-yl)ethanone (6k). 58% yield; brown oil; IR (CH2Cl2) νmax 3270.0, 3096.8, 2974.2, 1658.6, 1597.8, 1332.4, 1162.3 cm–1; 1H-NMR (400 MHz, CDCl3) δ 7.75 (dd, J = 8.2, 2.2 Hz, 2H), 7.67 (dd, J = 3.6, 1.2 Hz, 1H), 7.61 (d, J = 4.8 Hz, 1H), 7.25 (d, J = 9.6 Hz, 2H), 7.05–7.07 (m, 1H), 6.08 (d, J = 8.0 Hz, 1H), 5.11 (t, J = 4.4 Hz, 1H), 3.78 (q, J = 13.9 Hz, 3H), 3.20 (d, J = 5.2 Hz, 2H), 2.36 (s, 3H); 13C-NMR (100 MHz, CDCl3) δ 188.7, 144.2, 143.8, 143.6, 137.6, 134.6, 133.2, 133.1, 129.9, 128.4, 127.0, 99.4, 70.5, 69.9, 47.7, 44.3, 21.5; HRMS (ESI+) calcd for [C17H19NO5S2]+: m/z 382.0777, found 382.0781.
Methyl 2-{(2S,3aS,7aS)-3-tosyloctahydrobenzo[d]oxazol-2-yl}acetate (7a). 15% yield; white oil; IR (CH2Cl2) νmax 2916.8, 2848.7, 1715.4, 1631.7, 1349.0, 1160.9 cm–1; 1H-NMR (400 MHz, CDCl3) δ 8.38 (d, J = 8.0 Hz, 2H), 8.13 (d, J = 8.0 Hz, 2H), 5.26 (dd, J = 8.0, 4.0 Hz, 1H), 3.68 (s, 3H), 3.42–3.48 (m, 1H), 3.15 (ddd, J = 13.0, 9.0, 3.0 Hz, 1H), 2.74 (dd, J = 16.0, 4.0 Hz, 1H), 2.46 (s, 3H), 2.29–2.34 (m, 1H), 1.96–1.98 (m, 1H), 1.77–1.81 (m, 2H), 1.40–1.43 (m, 1H), 1.30–1.35 (m, 4H); 13C-NMR (100 MHz, CDCl3) δ 171.4, 152.2, 147.5, 143.2, 136.5, 127.2, 121.1, 118.0, 110.0, 88.1, 60.2, 50.9, 39.3, 37.4, 29.7, 21.4; GCMS (EI+) calcd for [C17H23NO5S]: m/z 354.4, found 355.0.
Ethyl 2-{(2S,3aS,7aS)-3-tosyloctahydrobenzo[d]oxazol-2-yl}acetate (7b). 37% yield; white oil; IR (CH2Cl2) νmax 2942.9, 1736.4, 1598.4, 1352.7, 1162.7 cm–1; 1H-NMR (400 MHz, CDCl3) δ 7.68 (d, J = 8.0 Hz, 2H), 7.34 (d, J = 8.0 Hz, 2H), 5.32 (dd, J = 9.6, 2.4 Hz, 1H), 4.15 (q, J = 7.2 Hz, 2H); 13C- NMR (100 MHz, CDCl3) δ 169.8, 144.4, 131.7, 130.0, 129.8, 128.2, 127.4, 88.3, 80.2, 64.5, 63.3, 60.7, 41.8, 29.6, 29.0, 24.4, 23.8, 23.3, 23.1, 21.6, 14.2; HRMS (ESI+) calcd for [C18H25NO5S]+: m/z 368.1526, found 368.1529.
Benzyl 2-{(2S,3aS,7aS)-3-tosyloctahydrobenzo[d]oxazol-2-yl}acetate (7c). 19% yield; yellow oil; IR (CH2Cl2) νmax 3032.7, 2940.8, 2862.9, 1710.7, 1620.9, 1320.5, 1121.0 cm–1; 1H-NMR (400 MHz, CDCl3) δ 7.74 (d, J = 8.0 Hz, 2H), 7.36–7.38 (m, 5H), 7.23 (d, J = 8.0 Hz, 2H), 5.10 (s, 1H), 5.07 (s, 1H), 4.88 (s, 1H), 3.67 (ddd, J = 10.0, 6.0, 2.0 Hz, 1H), 3.42 (t, J = 8.0 Hz, 1H), 3.06–3.11 (m, 1H), 2.78 (t, J = 8.0 Hz, 1H), 2.39 (s, 3H), 2.25–2.27 (m, 1H), 1.98–2.02 (m, 1H), 1.74–1.83 (m, 1H), 1.66–1.70 (m, 1H), 1.53–1.61 (m, 1H), 1.24–1.31 (m, 3H); 13C-NMR (100 MHz, CDCl3) δ 169.9, 167.1, 167.0, 163.4, 160.6, 149.1, 145.1, 144.9, 143.1, 137.1, 136.4, 136.1, 135.5, 135.3, 135.2, 130.0, 129.9, 129.5, 128.4, 127.3, 102.9, 102.8, 98.0, 79.6, 77.3, 67.3, 67.1, 66.2, 65.6, 55.8, 51.5, 32.2, 31.2, 29.6, 28.8, 28.0, 25.0, 23.2, 21.7, 21.5; GCMS (EI+) calcd for [C23H27NO5S]: m/z 429.5, found 430.0.
Phenyl 2-{(2S,3aS,7aS)-3-tosyloctahydrobenzo[d]oxazol-2-yl}acetate (7d). 13% yield; white solid; IR (CH2Cl2) νmax 3056.0, 2943.7, 1758.4, 1597.1, 1352.8, 1163.5 cm–1; 1H-NMR (400 MHz, CDCl3) δ 7.73 (d, J = 8.4 Hz, 2H), 7.36 (d, J = 8.4 Hz, 4H), 7.21–7.25 (m, 1H), 7.12 (dd, J = 5.0, 3.8 Hz, 2H), 5.44 (dd, J = 9.4, 2.6 Hz, 1H), 3.58–3.61 (m, 1H), 3.38 (dd, J = 16.2, 2.6 Hz, 1H), 3.05 (dd, J = 16.2, 9.0 Hz, 1H), 2.45–2.50 (m, 4H), 2.37 (ddd, J = 12.0, 8.0, 4.0 Hz, 1H), 1.84–2.07 (m, 1H), 1.81–1.84 (m, 2H), 1.51 (dd, J = 12.0, 3.6 Hz, 1H), 1.24–1.32 (m, 4H), 0.86–0.90 (m, 1H); 13C-NMR (100 MHz, CDCl3) δ 168.3, 150.5, 144.5, 131.6, 130.0, 129.4, 129.1, 128.2, 126.0, 121.6, 88.2, 80.6, 64.6, 42.1, 29.7, 29.1, 23.8, 23.3, 21.6; HRMS (ESI+) calcd for [C22H25NO5S]+: m/z 416.1526, found 416.1525.
1-{(2S,3aS,7aS)-3-Tosyloctahydrobenzo[d]oxazol-2-yl}propan-2-one (7e). 33% yield; yellow solid; IR (CH2Cl2) νmax 3060.9, 2943.0, 1717.2, 1598.3, 1351.3, 1162.1 cm–1; 1H-NMR (400 MHz, CDCl3) δ 7.63 (d, J = 8.4 Hz, 2H), 7.32 (d, J = 8.0 Hz, 2H), 5.30 (dd, J = 9.2, 2.0 Hz, 1H), 3.42 (ddd, J = 10.9, 9.1, 2.7 Hz, 1H), 3.13 (dd, J = 13.6, 6.0 Hz, 1H), 2.95 (dd, J = 17.2, 9.2 Hz, 1H), 2.36–2.43 (m, 5H), 2.21–2.27 (m, 1H), 2.17 (s, 3H), 1.94–1.96 (m, 1H), 1.71–1.77 (m, 2H), 1.36–1.46 (m, 1H), 1.15–1.23 (m, 4H); 13C-NMR (100 MHz, CDCl3) δ 205.4, 144.4, 131.5, 130.0, 128.1, 127.3, 87.7, 80.3, 64.3, 50.3, 30.7, 29.6, 29.3, 29.0, 23.7, 23.3, 21.6; HRMS (ESI+) calcd for [C17H23NO4S]+: m/z 338.1421, found 338.1416.
1-Phenyl-2-{(2S,3aS,7aS)-3-tosyloctahydrobenzo[d]oxazol-2-yl}ethanone (7f). 32% yield; yellow oil; IR (CH2Cl2) νmax 3056.0, 2942.4, 1687.0, 1597.5, 1350.5, 1162.7 cm–1; 1H-NMR (400 MHz, CDCl3) δ 7.99 (dd, J = 8.4, 1.2 Hz, 2H), 7.69 (d, J = 8.4 Hz, 2H), 7.54–7.58 (m, 1H), 7.47 (dd, J = 8.0, 7.2 Hz, 2H), 7.35 (d, J = 8.0 Hz, 2H), 5.57 (dd, J = 9.2, 2.0 Hz, 1H), 3.71 (dd, J = 17.2, 2.0 Hz, 1H), 3.48–3.54 (m, 2H), 2.49 (dd, J = 12.6, 2.2 Hz, 1H), 2.43 (s, 3H), 2.32 (ddd, J = 11.9, 8.7, 2.9 Hz, 1H), 1.81–2.02 (m, 1H), 1.75–1.81 (m, 2H), 1.50 (dd, J = 12.6, 3.0 Hz, 1H), 1.20–1.27 (m, 3H); 13C-NMR (100 MHz, CDCl3) δ 196.8, 144.5, 136.6, 133.4, 131.5, 130.0, 128.7, 128.3, 127.4, 88.3, 80.4, 64.4, 45.8, 29.6, 29.0, 23.8, 23.3, 21.6; HRMS (ESI+) calcd for [C22H25NO4S]+: m/z 400.1577, found 400.1582.
1-(3,4-Dichlorophenyl)-2-(3-tosyloctahydrobenzo[d]oxazol-2-yl)ethanone (7g). 18% yield; yellow solid; IR (CH2Cl2) νmax 3068.0, 2946.6, 2863.7, 1685.3, 1583.9, 1351.1, 1163.7 cm–1; 1H-NMR (400 MHz, CDCl3) δ 8.06 (s, 1H), 7.81 (dd, J = 10.0, 2.0 Hz, 1H), 7.68 (d, J = 8.0 Hz, 2H), 7.55 (d, J = 8.0 Hz, 1H), 7.36 (d, J = 8.0 Hz, 2H), 5.50 (dd, J = 10.0, 2.0 Hz, 1H), 3.68 (dd, J = 16.0, 4.0 Hz, 1H), 3.51 (td, J = 10.0, 4.0 Hz, 1H), 3.45 (dd, J = 18.0, 10.0 Hz, 1H), 2.48 (dd, J = 14.0, 2.0 Hz, 1H), 2.44 (s, 3H), 2.31 (ddd, J = 12.0, 8.0, 4.0 Hz, 1H), 1.97–1.99 (m, 1H), 1.76–1.82 (m, 2H), 1.45–1.54 (m, 1H), 1.20–1.27 (m, 3H); 13C-NMR (100 MHz, CDCl3) δ 194.6, 144.6, 138.0, 136.1, 133.4, 130.9, 130.3, 129.9, 128.3, 128.2, 127.5, 127.4, 127.3, 88.0, 80.5, 77.3, 64.3, 45.9, 29.6, 29.0, 23.8, 23.3, 21.6; GCMS (EI+) calcd for [C22H23Cl2NO4S]: m/z 468.4, found 468.1.
1-(3,4-Dimethoxyphenyl)-2-{(2S,3aS,7aS)-3-tosyloctahydrobenzo[d]oxazol-2-yl}ethanone (7h) 93% yield; yellow solid; IR (CH2Cl2) νmax 2938.9, 1672.7, 1596.0, 1348.4, 1161.1 cm–1; 1H-NMR (400 MHz, CDCl3) δ 7.61 (d, J = 8.4 Hz, 2H), 7.56 (dd, J = 8.4, 1.6 Hz, 1H), 7.46 (d, J = 2.0 Hz, 1H), 7.26 (d, J = 8.0 Hz, 2H), 7.16 (d, J = 8.0 Hz, 1H), 6.83 (d, J = 8.4 Hz, 1H), 5.48 (d, J = 7.6 Hz, 1H), 3.83 (s, 3H), 3.82 (s, 3H), 3.38–3.60 (m, 3H), 3.21 (ddd, J = 11.8, 7.8, 2.2 Hz, 1H), 2.21–2.40 (m, 5H), 1.84–1.92 (m, 2H), 1.61–1.70 (m, 3H), 1.37–1.46 (m, 2H), 1.11–1.18 (m, 4H); 13C-NMR (100 MHz, CDCl3) δ 195.4, 153.5, 149.0, 144.4, 143.2, 137.7, 131.4, 130.0, 129.7, 128.1, 127.0, 110.2, 88.5, 80.2, 72.9, 64.3, 59.6, 56.0, 54.3, 33.3, 31.5, 29.6, 29.0, 24.6, 23.7, 21.4; HRMS (ESI+) calcd for [C22H23Cl2NO4S]+: m/z 468.0798, found 468.0830.
1-(4-Fluorophenyl)-2-{(2S,3aS,7aS)-3-tosyloctahydrobenzo[d]oxazol-2-yl}ethanone (7i). 27% yield; yellow solid; IR (CH2Cl2) νmax 2942.4, 1687.2, 1597.4, 1350.7, 1162.6 cm–1; 1H-NMR (400 MHz, CDCl3) δ 8.01 (t, J = 4.4 Hz, 2H), 7.69 (d, J = 8.0 Hz, 2H), 7.35 (d, J = 8.0 Hz, 2H), 7.14 (t, J = 8.8 Hz, 2H), 5.53 (dd, J = 9.2, 1.6 Hz, 1H), 3.69 (dd, J = 17.0, 1.8 Hz, 1H), 3.44–3.54 (m, 2H), 2.42–2.50 (m, 5H), 2.31 (ddd, J = 11.7, 8.9, 3.1 Hz, 1H), 1.97–2.00 (m, 1H), 1.75–1.81 (m, 2H), 1.50 (ddd, J = 18.1, 12.1, 6.1 Hz, 1H), 1.19–1.27 (m, 3H); 13C-NMR (100 MHz, CDCl3) δ 195.2, 167.1, 164.6, 144.5, 134.3, 133.1, 133.0, 132.0, 131.7, 131.0, 128.2, 115.9, 88.2, 80.4, 64.4, 45.7, 31.5, 29.7, 23.9, 23.3, 21.6; HRMS (ESI+) calcd for [C22H24FNO4S]+: m/z 418.1483, found 418.1496.
1-(Naphth-1-yl)-2-{(2S,3aS,7aS)-3-tosyloctahydrobenzo[d]oxazol-2-yl}ethanone (7j). 33% yield; brown oil; IR (CH2Cl2) νmax 3056.0, 2942.5, 1678.0, 1596.5, 1350.8, 1162.5 cm–1; 1H-NMR (400 MHz, CDCl3) δ 8.75 (d, J = 8.4, 1H), 7.99 (d, J = 6.8 Hz, 2H), 7.86 (d, J = 8.0 Hz, 1H), 7.72 (d, J = 8.4 Hz, 2H), 7.51–7.61 (m, 4H), 7.33 (d, J = 8.0 Hz, 2H), 5.63 (dd, J = 9.2, 2.0 Hz, 1H), 3.88 (dd, J = 16.8, 2.0 Hz, 1H), 3.54–3.62 (m, 2H), 2.51 (d, J = 12.0 Hz, 1H), 2.41 (s, 3H), 2.35 (ddd, J = 11.7, 9.1, 3.1 Hz, 1H), 1.99–2.03 (m, 1H), 1.75–1.81 (m, 2H), 1.46–1.52 (m, 1H), 1.20–1.29 (m, 3H); 13C-NMR (100 MHz, CDCl3) δ 200.5, 144.5, 134.9, 134.0, 133.3, 131.5, 130.3, 130.0, 128.7, 128.5, 127.5, 127.4, 126.6, 124.4, 88.7, 80.4, 64.5, 48.9, 29.7, 29.1, 23.9, 23.8, 21.6; HRMS (ESI+) calcd for [C26H27NO4S]+: m/z 450.1734, found 450.1732.
1-(Thien-2-yl)-2-{(2S,3aS,7aS)-3-tosyloctahydrobenzo[d]oxazol-2-yl}ethanone (7k). 25% yield; brown solid; IR (CH2Cl2) νmax 2943.0, 1659.0, 1598.0, 1350.8, 1162.2 cm–1; 1H-NMR (400 MHz, CDCl3) δ 7.80 (dd, J = 3.8, 1.0 Hz, 1H), 7.69 (d, J = 8.4 Hz, 2H), 7.65 (dd, J = 5.0, 1.0 Hz, 1H), 7.35 (d, J = 8.0 Hz, 2H), 7.14 (dd, J = 5.0, 3.8 Hz, 1H), 5.51 (dd, J = 9.2, 2.0 Hz, 1H), 3.63 (dd, J = 16.4, 2.0 Hz, 1H), 3.54 (ddd, J = 10.9, 8.9, 2.9 Hz, 1H), 3.44 (dd, J = 16.2, 8.6 Hz, 1H), 2.41–2.49 (m, 4H), 2.31 (ddd, J = 12.2, 8.6, 3.0 Hz, 1H), 1.97–1.99 (m, 1H), 1.75–1.81 (m, 2H), 1.44–1.50 (m, 1H), 1.16–1.27 (m, 3H); 13C-NMR (100 MHz, CDCl3) δ 189.4, 144.5, 144.0, 134.2, 132.6, 131.5, 130.0, 128.3, 88.3, 80.4, 64.4, 46.4, 29.6, 29.0, 23.8, 23.3, 21.6; HRMS (ESI+) calcd for [C20H23NO4S2]+: m/z 406.1141, found 406.1136.
(2S,4S)-4-Isopropyl-3-tosyl-2-(tosylmethyl)oxazolidine (8a). 30% yield; white solid; IR (CH2Cl2) νmax 3064.1, 2963.9, 1597.1, 1350.3, 1318.9, 1163.7 cm–1; 1H-NMR (400 MHz, CDCl3) δ 7.82 (d, J = 8.4 Hz, 2H), 7.53 (d, J = 8.4 Hz, 2H), 7.37 (d, J = 8.0 Hz, 2H), 7.30 (d, J = 8.0 Hz, 2H), 5.13 (dd, J = 8.8, 1.2 Hz, 1H), 3.90 (dd, J = 14.2, 1.4 Hz, 1H), 3.74 (dd, J = 9.4, 2.2 Hz, 1H), 3.34–3.44 (m, 2H), 3.07 (dd, J = 9.2, 6.0 Hz, 1H), 2.46 (s, 3H), 2.42 (s, 3H), 1.78–1.87 (m, 1H), 0.94 (d, J = 6.8 Hz, 3H), 0.87 (d, J = 6.8 Hz, 3H); 13C-NMR (100 MHz, CDCl3) δ 145.0, 136.6, 132.9, 130.1 , 129.9, 128.3, 128.1, 128.0, 86.7, 68.4, 64.4, 61.6, 31.3, 21.7, 19,4, 18.2; HRMS (ESI+) calcd for [C21H27NO5S2]+: m/z 438.1403, found 438.1387.
(2S,4S)-4-Methyl-3-tosyl-2-(tosylmethyl)oxazolidine (8b). 68% yield; white oil; IR (CH2Cl2) νmax 3063.2, 2983.5, 1597.6, 1351.3, 1164.6 cm–1; 1H-NMR (400 MHz, CDCl3) δ 7.80 (d, J = 8.4 Hz, 2H), 7.56 (d, J = 13.6 Hz, 2H), 7.35 (d, J = 8.0 Hz, 2H), 7.28 (d, J = 8.0 Hz, 2H), 5.17 (d, J = 9.2 Hz, 1H), 3.85 (d, J = 14.4 Hz, 1H), 3.63 (ddd, J = 11.1, 6.7, 2.7 Hz, 1H), 3.36–3.48 (m, 3H), 2.43 (s, 3H), 2.40 (s, 3H), 1.25 (d, J = 6.4 Hz, 3H); 13C-NMR (100 MHz, CDCl3) δ 145.0, 144.7, 136.7, 132.7, 130.1, 129.9, 128.3, 127.8, 86.8, 73, 61.6, 54.8, 21.7, 21.6, 20.7; HRMS (ESI+) calcd for [C19H23NO5S2]+: m/z 410.1090, found 410.1094.
(2S,4S)-4-Benzyl-3-tosyl-2-(tosylmethyl)oxazolidine (8c). 65% yield; yellow oil; IR (CH2Cl2) νmax 3062.4, 3029.4, 2927.1, 1597.4, 1352.2, 1163.6 cm–1; 1H-NMR (400 MHz, CDCl3) δ 7.77 (d, J = 8.4 Hz, 2H), 7.59 (d, J = 8.0 Hz, 2H), 7.15–7.37 (m, 9H), 5.18 (dd, J = 9.2, 1.6 Hz, 1H), 3.73–3.81 (m, 2H), 3.66 (dd, J = 9.4, 3.4 Hz, 1H), 3.22 (dd, J = 9.2, 6.4 Hz, 1H), 3.08 (dd, J = 14.6, 9.4 Hz, 1H), 3.02 (dd, J = 13.6, 3.2 Hz, 1H), 2.84 (dd, J = 13.4, 9.4 Hz, 1H), 2.46 (s, 3H), 2.42 (s, 3H); 13C-NMR (100 MHz, CDCl3) δ 144.9, 136.7, 136.5, 132.8, 130.2, 129.8, 128.7, 128.3, 127.8, 127.0, 86.9, 69.5, 61.0, 59.8, 40.4, 21.7, 21.6; HRMS (ESI+) calcd for [C25H27NO5S2]+: m/z 486.1403, found 486.1403.
[(2S,4R)-3-Tosyl-2-(tosylmethyl)oxazolidin-4-yl]methanol (8d). 81% yield; white oil; IR (CH2Cl2) νmax 3532.6, 3063.3, 2928.6, 1597.3, 1351.3, 1164.0 cm–1; 1H-NMR (400 MHz, CDCl3) δ 7.78 (d, J = 8.0 Hz, 2H), 7.58 (d, J = 8.4 Hz, 2H), 7.33 (d, J = 8.0 Hz, 2H), 7.30 (d, J = 8.0 Hz, 2H), 5.24 (d, J = 8.8 Hz, 1H), 3.76–3.83 (m, 2H), 3.53–3.65 (m, 4H), 3.38 (dd, J = 9.2, 6.4 Hz, 1H), 2.82 (s, 1H), 2.42 (s, 3H), 2.41 (s, 3H); 13C-NMR (100 MHz, CDCl3) δ 145.1, 145.0, 136.6, 132.4, 130.3, 13.2, 129.9, 129.8, 128.2, 127.9, 87.1, 68.0, 62.8, 60.9, 59.7, 21.7, 21.6; HRMS (ESI+) calcd for [C19H23NO6S2]+: m/z 426.1040, found 426.1042.
(2S,3aS,7aS)-3-Tosyl-2-(tosylmethyl)octahydrobenzo[d]oxazole (8e). 37% yield; white oil; IR (CH2Cl2) νmax 3056.0, 2942.9, 1597.4, 1352.8, 1161.4 cm–1; 1H-NMR (400 MHz, CDCl3) δ 7.82 (d, J = 8.4 Hz, 2H), 7.44 (d, J = 8.4 Hz, 2H), 7.36 (d, J = 8.0 Hz, 2H), 7.29 (d, J = 8.0 Hz, 2H), 5.13 (dd, J = 9.4, 1.4 Hz, 1H), 3.83 (dd, J = 14.8, 1.6 Hz, 1H), 3.54 (dd, J = 14.8, 9.6 Hz, 1H), 3.30 (ddd, J = 11.8, 8.2, 2.0 Hz, 1H), 2.45 (s, 3H), 2.42 (s, 3H), 2.19–2.27 (m, 1H), 1.71–1.85 (m, 4H), 1.33–1.43 (m, 1H), 1.15–1.24 (m, 3H); 13C-NMR (100 MHz, CDCl3) δ 144.8, 136.8, 130.9, 130.3, 130.0, 128.4, 86.0, 80.8, 64.1, 60.7, 29.7, 29.5, 23.6, 23.2, 21.6; HRMS (ESI+) calcd for [C22H27NO5S2]+: m/z 450.1403, found 450.1406.