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
Asymmetric Synthesis of All Stereoisomers of α-Methylthreonine Using an Organocatalytic Steglich Rearrangement Reaction as a Key Step
作者:Harald Gröger、Friedrich Dietz
DOI:10.1055/s-0029-1217140
日期:——
An efficientsyntheticroute to all four stereoisomers of α-methylthreonine has been established. Each type of stereoisomer has been isolated in diastereomerically pure form and with an enantiomeric excess of at least 86% ee. The key step in this multi-step synthesis is an enantioselective organocatalytic Steglich rearrangement reaction of O-acetylated azlactones. The Steglich rearrangement was also