新奇分叉的不平常的氨基酸的所有四异构体与高 stereoselectivity 被设计并且综合(>90% de ) 并且在由 4 的使用(R/S ) 的 33%44% 全面收益是的 -5,5-dimethyl-4-phenyl-oxazolidin-2-one 经由不对称的 1,4-Michael 增加,直接或间接的 azidation,水解作用和加氢辅助的 chiral 反应。
All four isomers of a novel fl-branched unusual amino acid were designed and synthesized with high stereoselectivity (〉 90% de) and in 33%--44% overall yields by the use of 4(R/S)-5,5-dimethyl-4-phenyl-oxazolidin-2-one as the chiral auxiliary via asymmetric 1,4-Michael addition, direct or indirect azidation, hydrolysis and hydrogenation reactions.