*3.5. Synthesis of Optically Active Glycerol Derivatives*

*(R)-3-((tert-Butyldimethylsilyl)oxy)-2-hydroxypropyl 4-methylbenzenesulfonate* ((*R*)-**6**). To a solution of (*R*)-**2** (134 mg, 0.54 mmol) in CH2Cl2 (2.2 mL) was successively added imidazole (55.8 mg, 0.82 mmol) and TBSCl (123 mg, 0.82 mmol) at room temperature. After stirring for 6 h at the same temperature, the reaction was quenched with H2O. The resulting mixture was extracted with AcOEt. The combined organic layers were dried over Na2SO4, filtered, and concentrated under reduced pressure. The residue was purified by silica gel column chromatography (hexane/AcOEt = 2/1) to afford (*R*)-**6** (103 mg, 0.287 mmol, 87% yield) as a colorless oil; [α]D<sup>27</sup> −12.4 (*<sup>c</sup>* 1.01, AcOEt) for 94% ee; 1H NMR (400 MHz, CDCl3): *<sup>δ</sup>* 7.82–7.79 (m, 2H), 7.37–7.34 (m, 2H), 4.07 (dd, *J* = 9.9, 5.6 Hz, 1H), 4.01 (dd, *J* = 9.9, 5.6 Hz, 1H), 3.87–3.83 (m, 1H), 3.66–3.59 (m, 2H), 2.45 (s, 3H), 2.40 (d, *J* = 6.2 Hz, 1H), 0.85 (s, 9H), 0.039 (s, 3H), 0.035 (s, 3H); 13C{1H} NMR (100 MHz, CDCl3): *δ* 145.0, 132.6, 129.9, 128.0, 70.0, 69.2, 62.8, 25.7, 21.6, 18.1, −5.6; IR (ATR): 3537, 2930, 2857, 1360, 1252, 1175, 980, 833 cm<sup>−</sup>1; HRMS (EI) *m*/*z*: [M]+ calcd for C16H28O5SSi 360.1427, found 360.1429. HPLC analysis: Chiralpak AY-H, hexane/*i*-PrOH = 10/1, flow rate 1.0 mL/min, wavelength 254 nm, *t*<sup>R</sup> 22.4 min (minor) and 25.3 min (major).

*(R)-1-((tert-Butyldimethylsilyl)oxy)-3-(tosyloxy)propan-2-yl acetate* ((*R*)-**7**). To a solution of (*R*)-**6** (144 mg, 0.40 mmol) in pyridine (0.80 mL) was successively added DMAP (2.44 mg, 0.020 mmol) and Ac2O (49.0 mg, 0.48 mmol) at room temperature. After stirring for 2 h at the same temperature, the reaction mixture was diluted with toluene (5.0 mL) and concentrated under reduced pressure. The residue was purified by silica gel column chromatography (hexane/AcOEt = 5/1) to afford (*R*)-**7** (151 mg, 0.378 mmol, 94% yield) as a colorless oil. [α]D<sup>27</sup> −2.2 (*<sup>c</sup>* 1.24, AcOEt) for 94% ee; 1H NMR (400 MHz, CDCl3): *<sup>δ</sup>* 7.79 (d, *J* = 8.2 Hz, 2H), 7.35 (d, *J* = 8.0 Hz, 2H), 4.96–4.91 (m, 1H), 4.22 (dd, *J* = 10.7, 3.7 Hz, 1H), 4.17 (dd, *J* = 10.9, 5.4 Hz, 1H), 3.70–3.63 (m, 2H), 2.45 (s, 3H), 2.00 (s, 3H), 0.83 (s, 9H), 0.01 (s, 6H); 13C{1H} NMR (100 MHz, CDCl3): *δ* 170.0, 144.9, 132.7, 129.8, 128.0, 71.3, 67.8, 60.5, 25.6, 21.6, 20.8, 18.1, −5.58, −5.62; IR (ATR): 1744, 1362, 1233, 1175, 988, 833 cm−1; HRMS (EI) *m*/*z*: [M]+ calcd for C18H30O6SSi 402.1532, found 402.1533; HPLC analysis: Chiralpak AD, hexane/EtOH = 20/1, flow rate 1.0 mL/min, wavelength 254 nm, *t*<sup>R</sup> 4.8 min (major) and 6.5 min (minor).
