Improved synthetic methods for the preparation of three differently protected (2S,4R)-4-hydroxyornithines (10, 16, 24) have been developed which obviously can be used for the construction of the other stereoisomers. Formation of the corresponding α, β-didehydroamino acid derivatives (4, 15, 22) and their enantioselective hydrogenation are the characteristic steps of these syntheses.
已开发出用于制备三种不同保护的(2S,4R)-
4-羟基
鸟氨酸(10、16、24)的改进合成方法,这些方法显然可用于构建其他立体异构体。形成相应的α,β-二脱氢
氨基酸衍
生物(4、15、22)及其手性选择性氢化是这些合成过程的特征步骤。