and ɣ-oxonorvaline. These were synthesized in good yields (45–75%) from the common starting material (S)-allylglycine obtained by asymmetric transfer allylation of glycine Schiff base using the Corey catalyst derived from cinchonidine in more than 97% enantiomeric excess.
据报道,一种不同的对映选择性合成策略可生产非蛋白原性、具有
生物活性的天然
氨基酸正缬
氨酸、5-羟基-4-氧代-
L-正缬氨酸和ɣ-氧代正缬
氨酸。这些化合物以良好的产率(45-75%)从共同的起始材料(S)-烯丙基甘
氨酸中合成,该原料是通过甘
氨酸席夫碱的不对称转移烯丙基化获得的,使用衍生自
辛可尼丁的Corey催化剂,对映体过量超过97%。