Synthesis of Ethyl 6-Bromosorbate

Abstract

Ethyl 6-bromosorbate (1) is a useful intermediate for the preparation of Wittig and Horner-type reagents, which can be used in the synthesis of polyenes with a terminal carboxylic ester function or, as exemplified in recent syntheses of prostaglandins^1,2, for the preparation of alkanoic acid derivatives. Allylic bromination of ethyl sorbate following the procedures from literature^3,4,5- in our hands resulted in products containing variable amounts of the addition compound ethyl 4,5-dibromo-2-hexenoate. Isolation of pure 1 from this mixture is very difficult⁶.