Novel Catalytic Synthetic Route to Protected α-Methyl Threonine and the First Asymmetric Acetyl Migration in a Steglich Rearrangement Reaction
作者:Harald Gröger、Friedrich Dietz
DOI:10.1055/s-2008-1032104
日期:——
A short synthetic route to protected alpha-methyl threonine 5 as a representative example for (protected) alpha-methylated alpha-amino-beta-hydroxy acids bearing a stereogenic quaternary carbon center in a-position was developed. This multistep synthesis is based on the use of an easily accessible prochiral starting material in the presence of an organocatalyst, and allows the access to all four types
开发了一种短合成路线,以保护 α-甲基苏氨酸 5 作为(受保护的)α-甲基化 α-氨基-β-羟基酸的代表性例子,在 a 位具有立体季碳中心。这种多步合成基于在有机催化剂存在下使用易于获得的前手性起始材料,并允许获得所有四种类型的立体异构体。此外,实现了 Steglich 重排反应中的第一次对映选择性乙酰基迁移,这是该多步合成 5 的关键步骤。首次用于 Steglich 重排反应的杂环 12 被证明是一种有效的有机催化剂,其对映选择性高达 63% ee。