Diastereoselective synthesis of syn,syn- and syn,anti-2,4-diamino-3-hydroxyglutaric acid derivatives from ethyl α-acyl alaninates
作者:Carlos Alvarez-Ibarra、Aurelio G Csákÿ、Elena Martínez-Santos、Maria L Quiroga、JoséL Tejedor
DOI:10.1016/s0040-4020(99)00065-4
日期:1999.3
Syn,syn- and syn,anti-isomers of the four possible diastereomers of O,N,N'-protected 2,4-diamino-3-hydroxyglutaric acid derivatives 3-7 were diastereoselectively obtained. Syn,syn isomers of oxazolines 3 were selectively achieved by an aldol-like reaction in protic conditions between a-metallated ethyl isocyanoacetate 1 and alpha-acyl alaninates 2. Derivatives 4 with a syn,anti-configuration were obtained under epimerization reaction conditions, whereas derivatives 5-7 with syn,syn-configuration were selectively obtained under kinetic reaction conditions. (C) 1999 Elsevier Science Ltd. All rights reserved.