作者:Dieter Seebach、Johannes D. Aebi
DOI:10.1016/s0040-4039(01)81227-2
日期:1984.1
The lithium enolate 6 of methyl (2R,4S)-2--butyl-3-formyl-oxazolidine-4-carboxylate (4b) derived from (s)-(+)-serine can be generated with LDA in THF solution at −75°C. Alkylations (→ 9) and hydroxyalkylations (→ 10, 11) occur preferentially (>95:5) from the Re-face of the donor center (relative topicity lk). This stereochemical course is derived from the absolute configuration of 2-deuterio- and 2-methyl-serine
(2R,4S)-2--丁基-3-甲酰基-恶唑烷-4-羧酸甲酯(4b)的(2R,4S)-2-甲基丝氨酸的烯醇锂6可以在LDA溶液的THF溶液中于- 75℃。烷基化(→9)和羟烷基化(→ 10、11)优先(> 95:5)从供体中心的背面(相对局部性lk)出现。此立体化学过程从2- deuterio-和2-甲基-丝氨酸(的绝对构型衍生的12,13通过烯醇获得)6。