Synthesis of E-α,β-Unsaturated Esters via Hydration of Propargylic Acetates

Significance

Although there are several well-established methods to prepare trans-α,β-unsaturated alkenes (stabilized Wittig, HWE, cross-meta­thesis), depending on the substrates, they can lead to isomeric mixtures. Generally, the olefin isomers arise from reaction under equilibrium conditions, whereas the reaction above is proposed to be stereospecific and can thus lead to only one isomer. The authors report that the E-selectivity of the procedure is higher than that obtained with the commonly used HWE olefination.