A new and expeditious strategy for the synthesis of β-amino acids from Δ2-oxazolines
摘要:
A new, mild two-step synthesis of racemic p-amino acids starting from 2-allkyl-Delta (2)-oxazolines is described. The process implies the initial formation of masked N-substituted or N-unsubstituted beta -enamino acid derivatives followed by chemoselective reduction of the enamino moiety. The process takes place with high yields, total chemoselectivity and moderate diastereoselectivity. (C) 2001 Elsevier Science Ltd. All rights reserved.
Synthesis and C-alkylation of C-protected β-enamino acid derivatives from oxa- thia- and imidazolines
摘要:
Various heterocycles 3a-h can be readily metallated and condensed with a variety of organic nitriles to afford C-protected beta-enamino acid derivatives 1 (or 2). Procedures for alkylation of compounds 1 to obtain 2 as well as a "one-pot" preparation of 2 from 3 are also described. (C) 1999 Elsevier Science Ltd. All rights reserved.