[O:1]1[CH:5]=[CH:4][CH:3]=[C:2]1[CH:6]([CH2:25][CH2:26][CH2:27][CH3:28])[O:7][CH2:8][C:9]([O:11][CH:12]([C:19]1[CH:24]=[CH:23][CH:22]=[CH:21][CH:20]=1)[C:13]1[CH:18]=[CH:17][CH:16]=[CH:15][CH:14]=1)=[O:10].C1COCC1.C[Si]([N-][Si](C)(C)C)(C)C.[Na+].[CH2:44](Br)[C:45]1[CH:50]=[CH:49][CH:48]=[CH:47][CH:46]=1>CN(P(N(C)C)(N(C)C)=O)C>[CH2:44]([C@@H:8]([O:7][C@H:6]([C:2]1[O:1][CH:5]=[CH:4][CH:3]=1)[CH2:25][CH2:26][CH2:27][CH3:28])[C:9]([O:11][CH:12]([C:19]1[CH:24]=[CH:23][CH:22]=[CH:21][CH:20]=1)[C:13]1[CH:14]=[CH:15][CH:16]=[CH:17][CH:18]=1)=[O:10])[C:45]1[CH:50]=[CH:49][CH:48]=[CH:47][CH:46]=1.[O:1]1[CH:5]=[CH:4][CH:3]=[C:2]1[CH:6]([CH2:25][CH2:26][CH2:27][CH3:28])[O:7][CH2:8][C:9]([O:11][CH:12]([C:19]1[CH:24]=[CH:23][CH:22]=[CH:21][CH:20]=1)[C:13]1[CH:14]=[CH:15][CH:16]=[CH:17][CH:18]=1)=[O:10]Using the procedure in example 90 and (4S) benzhydryl 4-(2-furyl)-3-oxaoctanoate (5.0 g, 13.2 mmol), THF (50 mL), sodium bis(trimethylsilyl)amide (1.0M in THF, 14 mL, 14 mmol), and benzyl bromide (1.7 mL, 14 mmol) in 10 mL HMPA gave (2R,4S) benzhydryl 2-Benzyl-4-(2-furyl)-3-oxaoctanoate, 646.6 mg (10%) and 723 mg (12%) of the (2S 4S) diastereomer which was identical to the sample prepared in example 90. (2R,4S) diastereomer: [α]25D -34.8° (c 1.12, CHCl3); 1H NMR (300 MHz, CDCl3) δ 0.78 (t, 3H, J=7 Hz), 1.12 (m, 4H), 1.69 (m, 1H), 1.83 (m, 1H), 2.98 (m, 2H), 4.11 (t, 1H, J=7 Hz), 4.21 (dd, 1H, J=8 Hz), 6.07 (m, 2H), 6.72 (s, 1H), 7.26 (m, 16H); mass spectrum (FAB): 486 (M+NH4).
読み込み中…