反应详情

(2S,4S)-N-Benzoyl-2-(4'-methoxyphenyl)4-methyl-1,3-oxazolidin-5-one (17) was prepared from sodium N-(para-methoxybenzylidene)-(L)-alaninate (2.29 g, 10.0 mM) and benzoyl chloride (1.16 mL, 10.0 mM) following general procedure D and obtained as a white solid after purification by flash column chromatography, using 20% ethyl acetate/petrol as eluant (2.15 g, 69%, mixture of two diastereomers in a ratio of 3:1 by 1H NMR). After crystallisation from diethyl ether 17 was obtained as very fine white needles and as a single diastereomer by 1H NMR: [α]D20 +78.2 (c 1.0, CHCl3); mp 145-147° C.; IR (KBr): 1795, 1735, 1650 cm-1 ; 1H NMR (500 MHz, d8 -toluene, 90° C.): δ 6.80-7.21 (m, 5H), 6.51-6.53 (m, 4H), 6.43 (s, 1H), 4.44 (q, J=7 Hz, 1H), 3.29 (s, 3H), 1.25 (d, J=7 Hz, 3H); 13C NMR (50.3 MHz, CDCl3): 6172.5, 170.5, 160.6, 135.2, 130.9, 128.0, 127.6, 126.9, 126.8, 114.0, 90.3, 55.3, 52.7, 18.4; LRMS (NH3): 312 (MH+). Anal. Calcd for C18H17NO4 : C, 69.45; H: 5.46; N, 4.50.; found: C, 69.18; H, 5.55; is N, 4.38.

1. customobtained as a white solid
2. customafter purification by flash column chromatography
3. addition2.15 g, 69%, mixture of two diastereomers in a ratio of 3:1 by 1H NMR)
4. customAfter crystallisation from diethyl ether 17
5. customwas obtained as very fine white needles and as a single diastereomer by 1H NMR