反应详情

(2S,4S)-N-Benzyloxycarbonyl-2-(4'-methoxyphenyl)-4-methyl-1,3-oxazolidin-5-one (14) was prepared from sodium N-(para-methoxybenzylidene)-(L)-alaninate (2.29 g, 10.0 mM) and benzyl chloroformate (1.43 mL, 10.0 mM) following general procedure C and obtained as a white solid after purification by flash column chromatography, using 33% ethyl acetate/petrol as eluant (1.75g, 51%, single diastereomer): [α]D20 +99.9 (c 1.0, CHCl3); mp 97-99° C.; IR (KBr): 1790, 1695 cm-1 ; 1H NMR (500 MHz, d8 -toluene, 90° C.): δ 6.56-7.06 (m, 9H), 6.11 (s, 1H), 4.82 (d, J=12 Hz, 1H), 4.72 (d, J=12 Hz, 1H), 4.13 (q, J=7 Hz, 1H), 3.35 (s, 3H), 1.47 (d, J=7 Hz, 3H); 13C NMR (50.3 MHz, CDCl3): δ 172.3, 160.8, 152.0, 135.2, 128.4, 128.0, 127.7, 125.8, 121.3, 114.1, 89.2, 67.5, 55.3, 52.1, 16.5; LRMS (NH3): 342 (MNH4+). Anal. Calcd for C19H19NO5 : C, 66.85; H, 5.61; N, 4.10; found: C, 66.80; H, 5.42; N, 4.15.

1. customobtained as a white solid
2. customafter purification by flash column chromatography