3.1.4. Synthesis of Compounds **3aa**–**3da**, **3ab**–**3db**, **3ac**–**3dc**, **3ad**–**3dd**, and **10a**, **c**, **d**

Compounds **3aa–3da, 3ab–3db, 3ac–3dc, 3ad–3dd, and 10a, c, d** were synthesized from coumarins **6a–d** and the corresponding bromides **8a–d, 9** using DBU and DMF.

DBU (1.0 mmol) and corresponding bromide **8a–d, 9** (0.75 mmol) were added to compound **6a–d** (0.5 mmol) in dry DMF (5 mL) at room temperature under stirring. The reaction mixture was stirred at room temperature for 15 min and then heated at 60 ◦C for 5 h. H2O (15 mL) was added and the product was extracted with ethyl acetate. The extracts were washed with brine, dried with Na2SO4, and evaporated. The products **3aa–3da, 3ab–3db, 3ac–3dc, 3ad–3dd, and 10a, c, d** were isolated in the individual form **a**) by recrystallization from ethanol; or **b**) by column chromatography on silica gel using eluent–hexane, a solution containing from 25 to 100% ethyl acetate in hexane, and ethanol.

*(E)-7-(3,7-Dimethylocta-2,6-dienyloxy)-4-phenyl-2H-chromen-2-one 3aa.* Yield 56%, method **a**. M.p. 54 ◦C. HRMS: 374.1879 [M]+; calcd. 374.1877 (C25H26O3) +. <sup>1</sup>H NMR (CDCl3,δ ppm, *J*, Hz): 1.58 (br.s, 3H, CH3-24), 1.64 (m, 3H, all *J* < 1.5, CH3-23), 1.74 (m, 3H, all *J* < 1.5, CH3-25), 2.03-2.15 (m, 4H, 2H-19, 2H-20), 4.60 (d, 2H, *J*16,17 = 6.6, 2H-16), 5.06 (tm, 1H, *J*21,20 = 6.8, other *J* < 1.5, H-21), 5.45 (tm, 1H, *J*17,16 = 6.6, other *J* < 1.5, H-17), 6.18 (s, 1H, H-3), 6.77 (dd, 1H, *J*7,6 = 8.9, *J*7,9 = 2.5, H-7), 6.87 (d, 1H, *J*9,7 = 2.5, H-9), 7.34 (d, 1H, *J*6,7 = 8.9, H-6), 7.39-7.43 (m, 2H, H-11, H-15), 7.46-7.51 (m, 3H, H-12, H-13, H-14). <sup>13</sup>C NMR (δ ppm, CDCl3): 155.85 (s, C-1), 161.12 (s, C-2), 111.61 (d, C-3), 155.70 (s, C-4), 112.28 (s, C-5), 127.75 (d, C-6), 112.81 (d, C-7), 161.99 (s, C-8), 101.75 (d, C-9), 135.52 (s, C-10), 128.23 (d, C-11, C-15), 128.66 (d, C-12, C-14), 129.40 (d, C-13), 65.38 (t, C-16), 118.34 (d, C-17), 142.19 (s, C-18), 39.37 (t, C-19), 26.11 (t, C-20), 123.49 (d, C-21), 131.78 (s, C-22), 25.50 (k, C-23), 17.56 (k, C-24), 16.63 (k, C-25).

*(E)-7-(3,7-Dimethylocta-2,6-dienyloxy)-4-(4-fluorophenyl)-2H-chromen-2-one* **3ba**. Yield 35%, method **a**. M.p. 72 ◦C. HRMS: 392.1778 [M]+; calcd. 392.1782 (C25H25FO3) +. <sup>1</sup>H NMR (CDCl3,δ ppm, *J*, Hz): 1.58 (s, 3H, CH3-24), 1.64 (s, 3H, CH3-23), 1.74 (s, 3H, CH3-25), 2.02-2.16 (m, 4H, 2H-19, 2H-20), 4.60 (d, 2H, *J*16,17 = 6.5, 2H-16), 5.06 (tm, 1H, *J*21,20 = 6.8, other *J* < 2, H-21), 5.45 (tm, 1H, *J*17,16 = 6.5, other *J* < 2, H-17), 6.16 (s, 1H, H-3), 6.78 (dd, 1H, *J*7,6 = 8.9, *J*7,9 = 2.5, H-7), 6.87 (d, 1H, *J*9,7 = 2.5, H-9), 7.19 (dd, 2H, *J*12,11 = *J*14,15 = 8.7, *J*12(14),F = 8.7, H-12, H-14), 7.30 (d, 1H, *J*6,7 = 8.9, H-6), 7.41 (dd, 2H, *J*11,12 =*J*15,14 = 8.7, *J*11(15),F = 5.3, H-11, H-15). <sup>13</sup>C NMR (δ ppm, CDCl3, *J*C,F, Hz): 155.86 (s, C-1), 160.98 (s, C-2), 111.77 (d, C-3), 154.66 (s, C-4), 112.17 (s, C-5), 127.51 (d, C-6), 112.95 (d, C-7), 162.12 (d, C-8), 101.84 (d, C-9), 131.52 (s, <sup>4</sup> *J* = 3.4, C-10), 130.18 (d, <sup>3</sup> *J* = 8.3, C-11, C-15), 115.89 (d, <sup>2</sup> *J* = 21.4, C-12, C-14), 163.35 (s, <sup>1</sup> *J* = 250.0, C-13), 65.43 (t, C-16), 118.29 (d, C-17), 142.30 (s, C-18), 39.39 (t, C-19), 26.13 (t, C-20), 123.49 (d, C-21), 131.82 (s, C-22), 25.51 (k, C-23), 17.57 (k, C-24), 16.64 (k, C-25).

*(E)-4-(4-Bromophenyl)-7-(3,7-dimethylocta-2,6-dienyloxy)-2H-chromen-2-one* **3ca**. Yield 40%, method **a**. M.p. 80 ◦C. HRMS: 452.0979 [M]+; calcd. 452.0982 (C25H25BrO3) +. <sup>1</sup>H NMR (CDCl3,δ ppm, *J*, Hz): 1.58 (br.s, 3H, CH3-24), 1.64 (m, 3H, all *J* < 1.5, CH3-23), 1.74 (br.s, 3H, CH3-25), 2.03-2.14 (m, 4H, 2H-19, 2H-20), 4.59 (d, 2H, *J*16,17 = 6.6, 2H-16), 5.06 (tm, 1H, *J*21,20 = 6.7, other *J* ≤ 1.5, H-21), 5.44 (tm, 1H, *J*17,16 = 6.6, other *J* < 1.5, H-17), 6.16 (s, 1H, H-3), 6.78 (dd, 1H, *J*7,6 = 8.9, *J*7,9 = 2.5, H-7), 6.87 (d, 1H, *J*9,7 = 2.5, H-9), 7.28 (d, 1H, *J*6,7 = 8.9, H-6), 7.29 (br.d, 2H, *J*11,12 =*J*15,14 = 8.5, H-11, H-15), 7.63 (br.d, 2H, *J*12,11 = *J*14,15 = 8.5, H-12, H-14). <sup>13</sup>C NMR (δ ppm, CDCl3): 155.82 (s, C-1), 160.92 (s, C-2), 111.65 (d, C-3), 154.52 (s, C-4), 111.83 (s, C-5), 127.43 (d, C-6), 112.99 (d, C-7), 162.13 (c, C-8), 101.78 (d, C-9), 134.31 (s, C-10), 129.84 (d, C-11, C-15), 131.98 (d, C-12, C-14), 123.87 (s, C-13), 65.39 (t, C-16), 118.16 (d, C-17), 142.38 (s, C-18), 39.37 (t, C-19), 26.08 (t, C-20), 123.45 (d, C-21), 131.84 (s, C-22), 25.54 (k, C-23), 17.59 (k, C-24), 16.65 (k, C-25).

*(E)-7-(3,7-Dimethylocta-2,6-dienyloxy)-4-(4-methoxyphenyl)-2H-chromen-2-one* **3da.** Yield 29%, method **b**. HRMS: 404.1980 [M]+; calcd. 404.1982 (C26H28O4) +. <sup>1</sup>H NMR (CDCl3,δ ppm, *J*, Hz): 1.58 (s, 3H, CH3-24), 1.64 (m, 3H, all *J* < 2.0, CH3-23), 1.74 (m, 3H, all *J* < 1.5, CH3-25), 2.03-2.15 (m, 4H, 2H-19, 2H-20), 3.86 (s, 3H, CH3-26), 4.59 (d, 2H, *J*16,17 = 6.6, 2H-16), 5.06 (tm, 1H, *J*21,20 = 6.8, other *J* < 1.5, H-21), 5.45 (tm, 1H, *J*17,16 = 6.6, other *J* < 1.5, H-17), 6.16 (s, 1H, H-3), 6.78 (dd, 1H, *J*7,6 = 8.9, *J*7,9 = 2.5, H-7), 6.86 (d, 1H, *J*9,7 = 2.5, H-9), 7.00 (br.d, 2H, *J*12,11 = *J*14,15 = 8.7, H-12, H-14), 7.37 (br.d, 2H, *J*11,12 =*J*15,14 = 8.7, H-11, H-15), 7.41 (d, 1H, *J*6,7 = 8.9, H-6). <sup>13</sup>C NMR (δ ppm, CDCl3): 155.85 (s, C-1), 161.34 (s, C-2), 111.08 (d, C-3), 155.40 (s, C-4), 112.39 (s, C-5), 127.78 (d, C-6), 112.74 (d, C-7), 161.87 (s, C-8), 101.70 (d, C-9), 127.74 (s, C-10), 129.73 (d, C-11, C-15), 114.12 (d, C-12, C-14), 160.60 (s, C-13), 65.34 (t, C-16), 118.31 (d, C-17), 142.21 (s, C-18), 39.38 (t, C-19), 26.10 (t, C-20), 123.48 (d, C-21), 131.80 (s, C-22), 25.52 (k, C-23), 17.57 (k, C-24), 16.63 (k, C-25), 55.28 (k, C-26).

*7-(2-((1R,5S)-6,6-Dimethylbicyclo[3 1.1]hept-2-en-2-yl)ethoxy)-4-phenyl-2H-chromen-2-one* **3ab**. Yield 12%, method **b**. HRMS: 386.1872 [M]+; calcd. 386.1877 (C26H26O3) <sup>+</sup>. [α] 22 <sup>589</sup> = −20.0 (*c* = 0.53, CHCl3). <sup>1</sup>H NMR (CDCl3,δ ppm, *J*, Hz): 0.81 (c, 3H, CH3-26), 1.16 (d, 1H, *J*24a,24s = 8.6, H-24a), 1.26 (s, 3H, CH3-25), 2.05-2.11 (m, 2H, H-21, H-23), 2.20 (dm, 1H, *J*20,20<sup>0</sup> = 17.6, other *J* < 3.5, H-20), 2.26 (dm, 1H, *J*20<sup>0</sup> ,20 = 17.6, other *J* < 3.5, H-20<sup>0</sup> ), 2.37 (ddd, 1H, *J*24s,24a = 8.6, *J*24s,21 = *J*24s,23 = 5.6, H-24s), 2.40-2.52 (m, 2H, 2H-17), 3.98-4.06 (m, 2H, 2H-16), 5.32-5.36 (m, 1H, H-19), 6.18 (s, 1H, H-3), 6.74 (dd, 1H, *J*7,6 = 8.9, *J*7,9 = 2.5, H-7), 6.85 (d, 1H, *J*9,7 = 2.5, H-9), 7.34 (d, 1H, *J*6,7 = 8.9, H-6), 7.39-7.44 (m, 2H, H-11, H-15), 7.46-7.51 (m, 3H, H-12, H-13, H-14). <sup>13</sup>C NMR (δ ppm, CDCl3): 155.91 (s, C-1), 161.11 (s, C-2), 111.63 (d, C-3), 155.71 (s, C-4), 112.30 (s, C-5), 127.80 (d, C-6), 112.63 (d, C-7), 162.07 (s, C-8), 101.50 (d, C-9), 135.54 (s, C-10), 128.25 (d, C-11, C-15), 128.68 (d, C-12, C-14), 129.42 (d, C-13), 66.90 (t, C-16), 36.07 (t, C-17), 143.89 (s, C-18), 118.99 (d, C-19), 31.27 (t, C-20), 40.64 (d, C-21), 37.97 (c, C-22), 45.79 (d, C-23), 31.54 (t, C-24), 26.18 (k, C-25), 21.08 (k, C-26).

*7-(2-((1R,5S)-6,6-Dimethylbicyclo[3.1.1]hept-2-en-2-yl)ethoxy)-4-(4-fluorophenyl)-2H-chromen-2-one* **3bb**. Yield 37%, method **b**. HRMS: 404.1774 [M]+; calcd. 404.1782 (C26H25FO3) <sup>+</sup>. [α] 22 <sup>589</sup> = −17.4 (*c* = 0.78, CHCl3). <sup>1</sup>H NMR (CDCl3,δ ppm, *J*, Hz): 0.81 (s, 3H, CH3-26), 1.16 (d, 1H, *J*24a,24s = 8.6, H-24a), 1.26 (s, 3H, CH3-25), 2.06-2.10 (m, 2H, H-21, H-23), 2.20 (dm, 1H, *J*20,20<sup>0</sup> = 17.7, H-20), 2.27 (dm, 1H, *J*20<sup>0</sup> ,20 = 17.7, H-20<sup>0</sup> ), 2.36 (ddd, 1H, *J*24s,24a = 8.6, *J*24s,21 = *J*24s,23 = 5.6, H-24s), 2.40-2.51 (m, 2H, 2H-17), 4.02 (t, 2H, *J*16,17 = 7.0, 2H-16), 5.32-5.36 (m, 1H, H-19), 6.16 (s, 1H, H-3), 6.75 (dd, 1H, *J*7,6 = 8.9, *J*7,9 = 2.5, H-7), 6.84 (d, 1H, *J*9,7 = 2.5, H-9), 7.16-7.21 (m, 2H, *J*12,11 = *J*14,15 = 8.7, *J*12(14),F =8.7, H-12, H-14), 7.30 (d, 1H, *J*6,7 = 8.9, H-6), 7.38-7.43 (m, 2H, *J*11,12 = *J*15,14 = 8.7, *J*11(15),F = 5.3, H-11, H-15). <sup>13</sup>C NMR (δ ppm, CDCl3, *J*C,F, Hz): 155.90 (s, C-1), 160.94 (s, C-2), 111.76 (d, C-3), 154.64 (s, C-4), 112.16 (s, C-5), 127.54 (d, C-6), 112.74 (d, C-7), 162.18 (s, C-8), 101.57 (d, C-9), 131.51 (s, <sup>4</sup> *J* = 3.5, C-10), 130.18 (d, <sup>3</sup> *J* = 8.3, C-11, C-15), 115.88 (d, <sup>2</sup> *J* = 21.8, C-12, C-14), 66.93 (t, C-16), 36.05 (t, C-17), 143.86 (s, C-18), 119.02 (d, C-19), 31.27 (t, C-20), 40.64 (d, C-21), 37.97 (s, C-22), 45.79 (d, C-23), 31.54 (t, C-24), 26.17 (k, C-25), 21.08 (k, C-26).

*4-(4-Bromophenyl)-7-(2-((1R,5S)-6,6-dimethylbicyclo[3.1.1]hept-2-en-2-yl)ethoxy)-2H-chromen-2-one* **3cb**. Yield 15%, method **b**. [α] 26.6 <sup>589</sup> = <sup>−</sup>17.9 (*c* = 0.58, CHCl3). HRMS: 464.0988 [M]+; calcd. 450.0982 (C26H25BrO3) +. <sup>1</sup>H NMR (CDCl3,δ ppm, *J*, Hz): 0.80 (s, 3H, CH3-26), 1.15 (d, 1H, *J*24a,24s = 8.6, H-24a), 1.25 (s, 3H, CH3-25), 2.06-2.09 (m, 2H, H-21, H-23), 2.19 (dm, 1H, *J*20,20<sup>0</sup> = 17.6, H-20), 2.26 (dm, 1H, *J*20<sup>0</sup> ,20 = 17.6, H-20<sup>0</sup> ), 2.36 (ddd, 1H, *J*24s,24a = 8.6, *J*24s,21 = *J*24s,23 = 5.6, H-24s), 2.40-2.51 (m, 2H, 2H-17), 3.98-4.04 (m, 2H, 2H-16), 5.33-5.36 (m, 1H, H-19), 6.16 (s, 1H, H-3), 6.75 (dd, 1H, *J*7,6 = 8.9, *J*7,9 = 2.5, H-7), 6.84 (d, 1H, *J*9,7 = 2.5, H-9), 7.28 (d, 1H, *J*6,7 = 8.9, H-6), 7.28-7.31 (m, 2H, *J*11,12 = *J*15,14 = 8.4, H-11, H-15), 7.61-7.64 (m, 2H, *J*12,11 = *J*14,15 = 8.4, H-12, H-14). <sup>13</sup>C NMR (δ ppm, CDCl3): 155.86 (s, C-1), 160.87 (s, C-2), 111.65 (d, C-3), 154.49 (s, C-4), 111.81 (s, C-5), 127.44 (d, C-6), 112.79 (d, C-7), 162.19 (s, C-8), 101.50 (d, C-9), 134.30 (s, C-10), 129.84 (d, C-11, C-15), 131.97 (d, C-12, C-14), 123.86 (s, C-13), 66.87 (t, C-16), 36.01 (t, C-17), 143.78 (s, C-18), 119.03 (d, C-19), 31.23 (t, C-20), 40.54 (d, C-21), 37.95 (s, C-22), 45.65 (d, C-23), 31.51 (t, C-24), 26.14 (k, C-25), 21.08 (k, C-26).

*7-(2-((1R,5S)-6,6-Dimethylbicyclo[3.1.1]hept-2-en-2-yl)ethoxy)-4-(4-methoxyphenyl)-2H-chromen-2-one* **3db**. Yield 65%, method **b**. HRMS: 415.1906 [M-H]+; calcd. 415.1904 (C27H27O4) <sup>+</sup>. [α] 22 <sup>589</sup> = −15.7 (*c* = 0.75, CHCl3). <sup>1</sup>H NMR (CDCl3,δ ppm, *J*, Hz): 0.81 (s, 3H, CH3-27), 1.16 (d, 1H, *J*25a,25s = 8.6, H-25a), 1.26 (s, 3H, CH3-26), 2.05-2.11 (m, 2H, H-21, H-24), 2.19 (dm, 1H, <sup>2</sup> *J* = 17.6, H-21), 2.26 (dm, 1H, <sup>2</sup> *J* = 17.6, H-210 ), 2.36 (ddd, 1H, *J*25s,25a = 8.6, *J*25s,22 = *J*25s,24 = 5.6, H-25s), 2.40-2.51 (m, 2H, 2H-18), 3.86 (s, 3H, CH3-16), 4.02 (t, 2H, *J*17,18 = 7.0, H-17), 5.32-5.36 (m, 1H, H-20), 6.15 (s, 1H, H-3), 6.75 (dd, 1H, *J*7,6 = 8.9, *J*7,9 = 2.5, H-7), 6.83 (d, 1H, *J*9,7 = 2.5, H-9), 7.01 (br.d, 2H, *J*12,11 = *J*14,15 = 8.7, H-12, H-14), 7.37 (br.d, 2H, *J*11,12 = *J*15,14 = 8.7, H-11, H-15), 7.40 (d, 1H, *J*6,7 = 8.9, H-6). <sup>13</sup>C NMR (δ ppm, CDCl3): 155.93 (s, C-1), 161.28 (s, C-2), 111.12 (d, C-3), 155.38 (s, C-4), 112.43 (s, C-5), 127.81 (d, C-6), 112.54 (d, C-7), 161.97 (s, C-8), 101.49 (d, C-9), 127.79 (s, C-10), 129.74 (d, C-11, C-15), 114.16 (d, C-12, C-14), 160.64 (s, C-13), 55.30 (k, C-16), 66.88 (t, C-17), 36.07 (t, C-18), 143.90 (s, C-19), 118.97 (d, C-20), 31.27 (t, C-21), 40.64 (d, C-22), 37.97 (s, C-23), 45.79 (d, C-24), 31.54 (t, C-25), 26.17 (k, C-26), 21.08 (k, C-27).

*7-(((1R,5S)-6,6-Dimethylbicyclo[3.1.1]hept-2-en-2-yl)methoxy)-4-phenyl-2H-chromen-2-one* **3ac**. Yield 40%, method **a**. M.p. 106 ◦C. HRMS: 372.1717 [M]+; calcd. 372.1720 (C25H24O3) <sup>+</sup>. [α] 27.3 <sup>589</sup> = −25.33 (*c* = 1.02, EtOH). <sup>1</sup>H NMR (CDCl3,δ ppm, *J*, Hz): 0.82 (s, 3H, CH3-25), 1.18 (d, 1H, <sup>2</sup> *J* = 8.7, H-23a), 1.28 (s, 3H, CH3-24), 2.08-2.14 (m, 1H, H-20), 2.20 (ddd, 1H, *J*22,20 = *J*22,23s = 5.6, *J*22,18 = 1.4, H-22), 2.26 (dm, 1H, <sup>2</sup> *J* = 18.1, H-19), 2.33 (dm, 1H, <sup>2</sup> *J* = 18.1, H-190 ), 2.40 (ddd, 1H, <sup>2</sup> *J* = 8.7, *J*23s,20= *J*23s,22 = 5.6, H-23s), 4.44 (dm, 1H, <sup>2</sup> *<sup>J</sup>* <sup>=</sup> 12.4, other *<sup>J</sup>* <sup>≤</sup> 2.0, H-16), 4.47 (dm, 1H, <sup>2</sup> *J* = 12.4, other *J* ≤ 2.0, H-16<sup>0</sup> ), 5.61-5.64 (m, 1H, H-18), 6.19 (s, 1H, H-3), 6.77 (dd, 1H, *J*7,6 = 8.9, *J*7,9 = 2.5, H-7), 6.89 (d, 1H, *J*9,7 = 2.5, H-9), 7.33 (d, 1H, *J*6,7 = 8.9, H-6), 7.40-7.43 (m, 2H, H-11, H-15), 7.47-7.51 (m, 3H, H-12, H-13, H-14). <sup>13</sup>C NMR (δ ppm, CDCl3): 155.81 (s, C-1), 161.24 (s, C-2), 111.65 (d, C-3), 155.76 (s, C-4), 112.32 (s, C-5), 127.68 (d, C-6), 112.94 (d, C-7), 162.14 (s, C-8), 102.00 (d, C-9), 135.55 (s, C-10), 128.27 (d, C-11, C-15), 128.68 (d, C-12, C-14), 129.42 (d, C-13), 71.12 (t, C-16), 142.92 (s, C-17), 121.34 (d, C-18), 31.18 (t, C-19), 40.71 (d, C-20), 38.00 (s, C-21), 43.11 (d, C-22), 31.40 (t, C-23), 26.02 (k, C-24), 20.97 (k, C-25).

*7-(((1R,5S)-6,6-Dimethylbicyclo[3.1.1]hept-2-en-2-yl)methoxy)-4-(4-fluorophenyl)-2H-chromen-2-one* **3bc**. Yield 53%, method **b**. [α] 22.0 <sup>589</sup> = <sup>−</sup>15.6 (*c* = 0.68, CHCl3). HRMS: 390.1624 [M]+; calcd. 390.1626 (C25H23FO3) +. <sup>1</sup>H NMR (CDCl3,δ ppm, *J*, Hz): 0.81 (s, 3H, CH3-25), 1.17 (d, 1H, *J*23a,23s = 8.7, H-23a), 1.28 (s, 3H, CH3-24), 2.11 (ddtd, 1H, *J*20,22 = *J*20,23s = 5.6, *J*20,19 = 2.9, *J*20,18 = 1.3, H-20), 2.20 (ddd, 1H, *J*22,20 = *J*22,23s = 5.6, *J*22,18 = 1.4, H-22), 2.26 (dm, 1H, *J*19,19 , = 18.0, other *J* < 3.5, H-19), 2.33 (dm, 1H, *J*19<sup>0</sup> ,19 = 18.0, other *J* < 3.5, H-19<sup>0</sup> ), 2.40 (ddd, 1H, *J*23s,23a = 8.7, *J*23s,20= *J*23s,22 = 5.6, H-23s), 4.41-4.49 (m, 2H, 2H-16), 5.61-5.64 (m, 1H, H-18), 6.16 (s, 1H, H-3), 6.78 (dd, 1H, *J*7,6 = 8.9, *J*7,9 = 2.5, H-7), 6.88 (d, 1H, *J*9,7 = 2.5, H-9), 7.16-7.21 (m, 2H, *J*12,11 = *J*14,15 = 8.8, *J*12(14),F = 8.6, H-12, H-14), 7.29 (d, 1H, *J*6,7 = 8.9, H-6), 7.38-7.43 (m, 2H, *J*11,12 = *J*15,14 = 8.8, *J*11(15),F = 5.3, H-11, H-15). <sup>13</sup>C NMR (δ ppm, CDCl3, *J*C,F, Hz): 155.80 (s, C-1), 161.02 (s, C-2), 111.78 (d, C-3), 154.66 (s, C-4), 112.18 (s, C-5), 127.42 (d, C-6), 113.03 (d, C-7), 162.23 (s, C-8), 102.07 (d, C-9), 131.52 (s, <sup>4</sup> *J* = 3.5, C-10), 130.19 (d, <sup>3</sup> *J* = 8.3, C-11, C-15), 115.88 (d, <sup>2</sup> *J* = 21.8, C-12, C-14), 71.14 (t, C-16), 142.86 (s, C-17), 121.39 (d, C-18), 31.18 (t, C-19), 40.69 (d, C-20), 38.00 (s, C-21), 43.09 (d, C-22), 31.39 (t, C-23), 26.00 (k, C-24), 20.97 (k, C-25).

*4-(4-Bromophenyl)-7-(((1R,5S)-6,6-dimethylbicyclo[3.1.1]hept-2-en-2-yl)methoxy)-2H-chromen-2-one* **3cc**. Yield 36%, method **a**. M.p. 130 ◦C. HRMS: 450.0826 [M]+; calcd. 450.0825 (C25H23O3Br)+. [α] 26.4 <sup>589</sup> = <sup>−</sup>13.9 (*<sup>c</sup>* <sup>=</sup> 0.52, CHCl3). <sup>1</sup>H NMR (CDCl3,<sup>δ</sup> ppm, *<sup>J</sup>*, Hz): 0.80 (s, 3H, CH3-25), 1.16 (d, 1H, *<sup>J</sup>*23a,23s <sup>=</sup> 8.7, H-23a), 1.28 (s, 3H, CH3-24), 2.08-2.12 (m,1H, H-20), 2.19 (ddd, 1H, *J*22,20 = *J*22,23s = 5.6, *J*22,18 = 1.3, H-22), 2.25 (dm, 1H, *J*19,19 , = 18.0, other *J* < 3.5, H-19), 2.33 (dm, 1H, *J*<sup>19</sup> , ,19 = 18.0, other *J* < 3.5, H-190 ), 2.40 (ddd, 1H, *J*23s,23a = 8.7, *J*23s,20= *J*23s,22 = 5.6, H-23s), 4.43-4.48 (m, 2H, 2H-16), 5.60-5.63 (m, 1H, H-18), 6.16 (s, 1H, H-3), 6.78 (dd, 1H, *J*7,6 = 8.9, *J*7,9 = 2.5, H-7), 6.88 (d, 1H, *J*9,7 = 2.5, H-9), 7.27 (d, 1H, *J*6,7 = 8.9, H-6), 7.30 (d, 2H, *J*11,12 = *J*15,14 = 8.5, H-11, H-15), 7.63 (d, 2H, *J*12,11 = *J*14,15 = 8.5, H-12, H-14). <sup>13</sup>C NMR (δ ppm, CDCl3): 155.76 (s, C-1), 160.97 (s, C-2), 111.67 (d, C-3), 154.53 (s, C-4), 111.85 (s, C-5), 127.33 (d, C-6), 113.10 (d, C-7), 162.25 (s, C-8), 102.02 (d, C-9), 134.32 (s, C-10), 129.85 (d, C-11, C-15), 131.98 (d, C-12, C-14), 123.87 (s, C-13), 71.12 (t, C-16), 142.77 (s, C-17), 121.43 (d, C-18), 31.15 (t, C-19), 40.60 (d, C-20), 37.99 (s, C-21), 43.00 (d, C-22), 31.37 (t, C-23), 25.98 (k, C-24), 20.96 (k, C-25).

*7-(((1R,5S)-6,6-Dimethylbicyclo[3.1.1]hept-2-en-2-yl)methoxy)-4-(4-methoxyphenyl)-2H-chromen-2-one* **3dc**. Yield 55%, method **b**. M.p. 124 ◦C. [α] 30.6 <sup>589</sup> <sup>=</sup> <sup>−</sup>17.3 (*<sup>c</sup>* <sup>=</sup> 0.82, CHCl3). HRMS: 402.1820 [M]+; calcd. 402.1827 (C26H26O4) +. <sup>1</sup>H NMR (CDCl3,δ ppm, *J*, Hz): 0.81 (s, 3H, CH3-26), 1.17 (d, 1H, *J*24a,24s = 8.7, H-24a), 1.28 (s, 3H, CH3-25), 2.10 (ddtd, 1H, *J*21,23 = *J*21,24s = 5.6, *J*21,20 = 2.8, *J*21,19 = 1.3, H-21), 2.20 (ddd, 1H, *J*23,21 = *J*23,24s = 5.6, *J*23,19 = 1.4, H-23), 2.25 (dm, 1H, *J*20,20 , = 18.0, other *J* < 3.0, H-20), 2.33 (dm, 1H, *J*20<sup>0</sup> ,20 = 18.0, other *J* < 3.5, H-20<sup>0</sup> ), 2.40 (ddd, 1H, *J*24s,24a = 8.7, *J*24s,21= *J*24s,23 = 5.6, H-24s), 3.85 (s, 3H, CH3-16), 4.41-4.49 (m, 2H, 2H-17), 5.60-5.63 (m, 1H, H-19), 6.14 (s, 1H, H-3), 6.77 (dd, 1H, *J*7,6 = 8.9, *J*7,9 = 2.5, H-7), 6.86 (d, 1H, *J*9,7 = 2.5, H-9), 7.00 (br.d, 2H, *J*12,11 = *J*14,15 = 8.8, H-12, H-14), 7.36 (br.d, 2H, *J*11,12 = *J*15,14 = 8.8, H-11, H-15), 7.39 (d, 1H, *J*6,7 = 8.9, H-6). <sup>13</sup>C NMR (δ ppm, CDCl3): 155.80 (s, C-1), 161.30 (s, C-2), 111.11 (d, C-3), 155.36 (s, C-4), 112.41 (s, C-5), 127.67 (d, C-6), 112.79 (d, C-7), 161.99 (s, C-8), 101.96 (d, C-9), 127.77 (s, C-10), 129.72 (d, C-11, C-15), 114.13 (d, C-12, C-14), 160.62 (s, C-13), 55.27 (k, C-16), 71.06 (t, C-17), 142.91 (s, C-18), 121.26 (d, C-19), 31.15 (t, C-20), 40.67 (d, C-21), 37.97 (s, C-22), 43.07 (d, C-23), 31.37 (t, C-24), 25.99 (k, C-25), 20.94 (k, C-26).

*7-(((1S,5R)-6,6-Dimethylbicyclo[3.1.1]hept-2-en-2-yl)methoxy)-4-phenyl-2H-chromen-2-one* **3ad**. Yield 46%, method **b**. [α] 26.6 <sup>589</sup> = +23.33 (*c*=1.02, EtOH). HRMS: 372.1718 [M]+; calcd. 372.1720 (C25H24O3) +. The <sup>1</sup>H and <sup>13</sup>C NMR spectra of **3ad** correspond to the spectra of the enantiomer **3ac**.

*7-(((1S,5R)-6,6-Dimethylbicyclo[3.1.1]hept-2-en-2-yl)methoxy)-4-(4-fluorophenyl)-2H-chromen-2-one* **3bd**. Yield 35%, method **a**. M.p. 129 ◦C. HRMS: 390.1628 [M]+; calcd. 390.1626 (C25H23FO3) <sup>+</sup>. [α] 22.0 589 = +22.3 (CHCl3, *c* = 0.53). The <sup>1</sup>H and <sup>13</sup>C NMR spectra of **3bd** correspond to the spectra of the enantiomer **3bc**.

*4-(4-Bromophenyl)-7-(((1S,5R)-6,6-dimethylbicyclo[3.1.1]hept-2-en-2-yl)methoxy)-2H-chromen-2-one 3cd*. Yield 39%, method **a**. M.p. 138 ◦C. HRMS: 450.0825 [M]+; calcd. 450.0820 (C25H23BrO3) <sup>+</sup>. [α] 26.7 589 = +22.4 (*c* = 0.58, CHCl3). The <sup>1</sup>H and <sup>13</sup>C NMR spectra of **3cd** correspond to the spectra of the enantiomer **3cc**.

*7-(((1S,5R)-6,6-Dimethylbicyclo[3.1.1]hept-2-en-2-yl)methoxy)-4-(4-methoxyphenyl)-2H-chromen-2-one 3dd*. Yield 33%, method **a**. M.p. 112 ◦C. HRMS: 402.1823 [M]+; calcd. 402.1827 (C26H26O4) <sup>+</sup>. [α] 22.0 589 = +20.8 (*c* = 0.72, CHCl3). The <sup>1</sup>H and <sup>13</sup>C NMR spectra of **3dd** correspond to the spectra of the enantiomer **3dc**.

*7-(Benzyloxy)-4-phenyl-2H-chromen-2-one* **10a**. Yield 42%, method **b**. M.p. 92 ◦C. HRMS: 328.1093 [M]+; calcd. 328.1094 (C22H16O3) +. <sup>1</sup>H NMR (CDCl3,δ ppm, *J*, Hz): 5.13 (s, 2H, 2H-16), 6.19 (s, 1H, H-3), 6.85 (dd, 1H, *J*7,6 = 8.9, *J*7,9 = 2.5, H-7), 6.94 (d, 1H, *J*9,7 = 2.5, H-9), 7.31-7.35 (m, 1H, H-20), 7.35–7.44 (m, 7H, H-6, H-11, H-15, H-18, H-19, H-21, H-22), 7.46-7.52 (m, 3H, H-12, H-13, H-14). <sup>13</sup>C NMR (δ ppm, CDCl3): 155.80 (s, C-1), 161.00 (s, C-2), 111.86 (d, C-3), 155.62 (s, C-4), 112.62 (s, C-5), 127.88 (d, C-6), 112.80 (d, C-7), 161.71 (s, C-8), 102.09 (d, C-9), 135.44 (s, C-10), 128.23 (d, C-11, C-15), 128.68 (d, C-12, C-14), 129.44 (d, C-13), 70.39 (t, C-16), 135.67 (s, C-17), 127.35 (d, C-18, C-22), 128.62 (d, C-19, C-21), 128.23 (d, C-20).

*7-(Benzyloxy)-4-(4-bromophenyl)-2H-chromen-2-one* **10c**. Yield 25%, method **a**. M.p. 128 ◦C. HRMS: 406.0204 [M]+; calcd. 406.0199 (C22H15BrO3) +. <sup>1</sup>H NMR (CDCl3,δ ppm, *J*, Hz): 5.13 (s, 2H, 2H-16), 6.17 (s, 1H, H-3), 6.86 (dd, 1H, *J*7,6 = 8.9, *J*7,9 = 2.5, H-7), 6.94 (d, 1H, *J*9,7 = 2.5, H-9), 7.29 (dm, 2H, *J*11,12 = *J*15,14 = 8.5, H-11, H-15), 7.31 (d, 1H, *J*6,7 = 8.9, H-6), 7.32-7.35 (m, 1H, H-20), 7.37-7.43 (m, 4H, H-18, H-19, H-21, H-22), 7.63 (dm, 2H, *J*12,11 = *J*14,15 = 8.5, H-12, H-14). <sup>13</sup>C NMR (δ ppm, CDCl3): 155.79 (s, C-1), 160.81 (s, C-2), 111.92 (d, C-3), 154.46 (s, C-4), 112.18 (s, C-5), 127.56 (d, C-6), 113.02 (d, C-7), 161.86 (s, C-8), 102.14 (d, C-9), 134.24 (s, C-10), 129.83 (d, C-11, C-15), 132.01 (d, C-12, C-14), 123.92 (s, C-13), 70.42 (t, C-16), 135.54 (s, C-17), 127.38 (d, C-18, C-22), 128.66 (d, C-19, C-21), 128.30 (d, C-20).

*7-(Benzyloxy)-4-(4-methoxyphenyl)-2H-chromen-2-one* **10d**. Yield 34%, method **b**. M.p. 143 ◦C. HRMS: 358.1198 [M]+; calcd. 358.1200 (C23H18O4) +. <sup>1</sup>H NMR (CDCl3,δ ppm, *J*, Hz): 3.86 (s, 3H, CH3-16), 5.12 (s, 2H, 2H-17), 6.16 (s, 1H, H-3), 6.85 (dd, 1H, *J*7,6 = 8.9, *J*7,9 = 2.5, H-7), 6.93 (d, 1H, *J*9,7 = 2.5, H-9), 7.01 (dm, 2H, *J*12,11 = *J*14,15 = 8.7, H-12, H-14), 7.30-7.35 (m, 1H, H-21), 7.35–7.45 (m, 7H, H-6, H-11, H-15, H-19, H-20, H-22, H-23). <sup>13</sup>C NMR (δ ppm, CDCl3): 155.82 (s, C-1), 161.18 (s, C-2), 111.34 (d, C-3), 155.30 (s, C-4), 112.75 (s, C-5), 127.90 (d, C-6), 112.72 (d, C-7), 161.61 (s, C-8), 102.07 (d, C-9), 127.68 (s, C-10), 129.72 (d, C-11, C-15), 114.16 (d, C-12, C-14), 160.65 (s, C-13), 55.29 (k, C-16), 70.37 (t, C-17), 135.70 (s, C-18), 127.36 (d, C-19, C-23), 128.61 (d, C-20, C-22), 128.22 (d, C-21).
