Synthesis of L-Erythro-α,β-Dihydroxy-GABA and γ-Hydroxy-L-Erythronine by Oxidative Degradation of Amino-4-Pentenediols

The regioisomeric epoxy-4-pentenols B and D, readily accessible from 1,4-pentadiene-3-ol A in high stereoisomer purity by Sharpless epoxidation, have been shown to produce various regio- and stereoisomers of amino-4-pentenediols in a controlled manner. The N-protected derivatives of 1- and 3-aminopentenediols 2 and 11, respectively, are suitable for oxidative degradation to amino acid derivatives. Subsequent hydrolysis provides the rare amino-dihydroxy-butyric acid hydrochlorides 9 and 15.