Structure and total synthesis of benzylthiocrellidone, a novel dimedone-based vinyl sulfide from the sponge Crella spinulata

Abstract

A concise synthesis of the yellow pigment benzylthiocrellidone 1, based on a Michael addition–elimination of dimedone 2 to the ketene thioacetal 7 derived from dimedone, benzyl bromide and carbon disulfide, is described. The synthetic pigment had an X-ray crystal structure identical to that measured for the natural product.