One-pot Eschenmoser episulfide contractions in DMSO: applications to the synthesis of fuligocandins A and B and a number of vinylogous amides.

Practical total syntheses of the natural products fuligocandin A (2a) and fuligocandin B (3) have been achieved through a convergent strategy depending on the Eschenmoser episulfide contraction as a key step. Conducting the reaction in DMSO proved to be an efficient and general method for the synthesis of a variety of vinylogous amides, such as azepan-2-ylidenepropan-2-one.