Chemo‐, Regio‐ and Stereoselective Preparation of (Z)‐2‐Butene‐1,4‐Diol Monoesters via Pd‐Catalyzed Decarboxylative Acyloxylation

Abstract

Abstract(Z)‐alkenes are useful synthons but thermodynamically less stable than their (E)‐isomers and typically more difficult to prepare. The synthesis of 1,4‐hetero‐bifunctionalized (Z)‐alkenes is particularly challenging due to the inherent regio‐ and stereoselectivity issues. Herein we demonstrate a general, chemoselective and direct synthesis of (Z)‐2‐butene‐1,4‐diol monoesters. The protocol operates within a Pd‐catalyzed decarboxylative acyloxylation regime involving vinyl ethylene carbonates (VECs) and various carboxylic acids as the reaction partners under mild and operationally attractive conditions. The newly developed process allows access to a structurally diverse pool of (Z)‐2‐butene‐1,4‐diol monoesters in good yields and with excellent regio‐ and stereoselectivity. Various synthetic transformations of the obtained (Z)‐2‐butene‐1,4‐diol monoesters demonstrate how these synthons are of great use to rapidly diversify the portfolio of these formal desymmetrized (Z)‐alkenes.