New synthetic strategies for five membered heterocycles via novel organosulfur synthons

Abstract

For several years, our research group has been involved in design and development of novel organosulfur building blocks and their synthetic applications for construction of substituted and fused five/six membered heterocycles. In this chapter, a brief account of these intermediates has been given. 1.1 Polarized Ketene Dithioacetals The versatile synthon family of polarized ketene dithioacetals of the general structure A has been proven to be among the simplest and useful synthetic building blocks in various organic transformations.1 Among them, the corresponding α-oxoketene dithioacetals have been extensively studied by our research group.1a-b These organosulfur synthons can easily be prepared by the reaction of CS2 with various active methylene ketones in the presence of base followed by alkylation in one-pot reaction (Scheme 1).