3-Acetyl-2, 5-Dihydrothiophene-1, 1-Dioxide as a Stable Precursor of 2-Acetyl-1, 3-Butadiene

Abstract Our interest1 in the development of new methodology for the synthesis of heterocyclic analogues of the anthra-cyclines led us to contemplate the use of 2-acetylbutadiene as a building block. This diene was anticipated to display too high reactivity for handling as a shelf chemical by analogy with related 2-substituted dienes2 so that its effective use would necessitate trapping conditions allowing its concomitant in situ generation from a storable precursor3. An attractive latent generator of this building block is 3-acetyl-2,5-dihydrothiophene-1,1-dioxide (1) which upon thermal extrusion of SO2 in the presence of a dienophile would allow controlled and effective utilization of the diene fragment.