Stereoselective functionalisation of cis- and trans-2-ferrocenyl-3-pivaloyl-4-alkyl-1,3-oxazolidin-5-ones: asymmetric synthesis of (R)- and (S)-2-alkyl-2-aminopent-4-enoic acids and (2R,3S)-2-amino-2-methyl-3-hydroxy-3-phenylpropanoic acid
作者:Francisco Alonso、Stephen G. Davies、Almut S. Elend、Michael A. Leech、Paul M. Roberts、Andrew D. Smith、James E. Thomson
DOI:10.1039/b814453b
日期:——
of allyl bromide promotes highly stereoselective allylation (>98% de) at the 4-position of the oxazolidinone ring anti to the stereodirecting 2-ferrocenyl group. Hydrolysis of the resultant 4,4-disubstituted oxazolidinones (>98% de) yields enantiomeric (R)- and (S)-2-alkyl-2-aminopent-4-enoic acids in high ee. Furthermore, the aldolreaction of the lithium enolate of cis-2-ferrocenyl-3-pivaloyl-4-methyl-1