HClO4·SiO2-mediated Improved Isomerization of Glycidic Esters to α-Hydroxy-β,γ-unsaturated Esters: Application in the Formal Synthesis of (R)-Baclofen and β-Phenyl GABA Analogues

Abstract An efficient isomerization of glycidic esters to corresponding allylic alcohols, viz. α-hydroxy-β,γ-unsaturated esters has been brought about using HClO4·SiO2. Five of these allylic alcohols underwent selective SN2′ nucleophilic substitution to generate γ-azido-α,β-unsaturated esters which were readily converted to an antispastic drug Baclofen and four other β-phenyl GABA analogues.