Asymmetric Synthesis of All Stereoisomers of α-Methylthreonine Using an Organocatalytic Steglich Rearrangement Reaction as a Key Step

Abstract

An efficient synthetic route 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 extended to other substrates.

Key words

acylation - amino acids - asymmetric catalysis - rearrangements - stereoselective synthesis

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11

Aldrich Technical Bulletin, AL-218, 2004.