反应详情

(2S,4S)-4-Benzyl-N-benzyloxycarbonyl-2-(4'-methoxyphenyl)-1,3-oxazolidin-5-one (13) was prepared from sodium N-(para-methoxybenzylidene)-(L)-phenylalaninate (3.05 g, 10.0 mM) and benzyl chloroformate (1.43 mL, 10.0 mM) following general procedure C and obtained as a white solid after crystallisation from diethyl ether (2.87 g, 69%): [α]D20 +50.1 (c 1.0, CHCl3); mp 85° C.; IR (KBr): 1795, 1700 cm-1 ; 1H NMR (500 MHz, d8 -toluene, 90° C.): δ 6.49-7.08 (m, 14H), 6.04 (s, 1H), 4.92 (d, J=12 Hz, 1H), 4.83 (d, J=12 Hz, 1H), 4.19 (dd, J=4, 6 Hz, 1H), 3.39 (s, 3H), 3.25 (dd, J=6, 14 Hz, 1H), 3.08 (dd, J=4, 14 Hz, 1H); 13C NMR (50.3 MHz, CDCl3): δ 171.4, 160.3, 151.5, 135.3, 129.2, 128.8, 128.5, 128.2, 127.3, 113.4, 89.3, 67.8, 58.4, 55.3, 34.5; LRMS (EI): 418 (MH+). Anal. Calcd for C25H23NO5 : C, 71.93; H, 5.55; N, 3.35. Found: C, 72.22; H, 5.36; N, 3.28.

1. customobtained as a white solid
2. customafter crystallisation from diethyl ether (2.87 g, 69%)