反应详情

温度

64 °C

To a solution of tert-Butyl cholest-5-en-3β-yloxyacetate (general formula XII, where n2=1; 111 mg, 0.22 mmol) in diethyl ether (8 ml) formic acid (5 ml, 132 mmol) was added and the solution was stirred at 64° C. for 5 h. The solvents were evaporated in vacuo and the residue was lyophilized from dioxane (20 ml) to afford Cholest-5-en-3β-yloxyacetic acid (general formula IX, where n2=1; 99 mg, 100%). 1H NMR (400 MHz, CDCl3) δ (ppm): 5.33-5.41 m, 1H (H-6); 4.16 s, 2H (H-1′); 3.31 tt, J=11.20, 4.60 Hz, 1H (H-3); 2.35-2.43 m, 1H (H-4a); 2.23-2.33 m, 1H (H-4b); 1.76-2.07 m, 5H (CH-1, H-12, H-2, H-7, H-16); 1.01 s, 3H (CH3-19); 0.92 d, J=6.57 Hz, 3H (CH3-21); 0.88 d, J=1.77 Hz, 3H (CH3-26); 0.86 d, J=1.64 Hz, 3H (CH3-27); 0.79-1.67 m, 33H (cholesteryl); 0.68 s, 3H (CH3-18); 13C NMR (101 MHz, CDCl3) δ (ppm): 172.98 (C-2′) 139.88 (C-5) 122.45 (C-6) 80.49 (C-1) 65.20 (C-1′) 56.72 (C-14) 56.15 (C-17) 50.10 (C-9) 42.31 (C-13) 39.73 (C-12) 39.51 (C-24) 38.69 (C-4) 36.96 (C-1) 36.76 (C-10) 36.18 (C-22) 35.78 (C-20) 31.91 (C-7) 31.85 (C-8) 28.21 (C-2) 28.10 (C-16) 28.01 (C-25) 24.27 (C-15) 23.82 (C-23) 22.81 (C-26) 22.55 (C-27) 21.06 (C-11) 19.32 (C-19) 18.71 (C-21) 11.86 (C-18); for C29H48O3 monoisotopic mass: calculated: 444.4. found: MS ESI m/z: 467.9 [M+Na]+. for C29H48O3—Na+ HR-MS calculated: 467.3496. found: 467.3496; IR (CHCl3): 3517, 1783, 1731, 1287 (COOH); 1133, 1110, 1087, 1070, 842 (ether); 1668, 1334 (C═C); 1381, 1367, 1170 (i-propyl); 2954, 2869, 1443, 1367 (Me); [α]D −16.1° (c 0.031; CHCl3).

1. customThe solvents were evaporated in vacuo