There is a considerable interest in synthetic and naturally occurring thiazolidine derivatives containing the exocyclic double bond, in part due to their broad range of biological activity1 and, in part because they exhibit increasing enaminic reactivity toward electrophiles which can be exploited for the preparation of precursors leading to push-pull polyenes. 24 We have recently reported the first regioselective synthesis of 2-alkylidene-4-oxothiazolidine ...