3-Amino-5,6-dihydro-4H-thiopyran 1,1-dioxides. Reactivity with diethyl azodicarboxylate and some α,β-unsaturated ketones

Abstract

The secondary enamines derived from 5,6-dihydro-2H-thiopyran-3(4H)-one 1,1-dioxide are in tautomeric equilibrium with their imine forms. With the title electrophiles, either they react at nitrogen or show the usual reactivity at the β-carbon atom of the enamine system. With electrophilic olefins carbocyclization compounds are also formed.