Regioselective synthesis of new 5-ethoxycarbonylmethyl-4-oxothiazolidin-2-ylidene bromides and rearrangement reaction thereof

Abstract

(Z)-5-Substituted-2-alkylidene-4-oxothiazolidine derivatives 2a-c were regioselectively brominated to afford the new, synthetically useful vinyl bromides 3a-c, They undergo novel rearrangement reaction to provide 4-oxothiazolidine derivatives 5a-c containing two fully conjugated exocyclic double bonds. Extremely clean and efficient derivatization of 2a-c to 5a-c was also achieved by a one-pot three-step sequence under mild experimental conditions without isolation of vinyl bromides 3a-c.