5+1]-Annulation Strategy Based on Alkenoyl Ketene Dithioacetals and Analogues

Abstract

Functionalized ketene dithioacetals are versatile intermediates in organic synthesis. The important multiple roles of the dialkylthio group make these substrates particularly useful for the synthesis of a number of important classes of substituted carbo- and heterocyclic systems, such as thiophenes, lactones, pyrroles, furans, pyridines, substituted cyclohexanones, and benzene derivatives. This account focuses on the utility of alkenoyl ketene dithioacetals, which have been found useful in the synthesis of six-membered carbo- and heterocyclic systems relying upon utilization of alkenoyl ketene dithioacetals, as the 1,5-bielectrophilic component in the [5+1] annulation with carbon, nitrogen, sulfur, and other nucleophiles.