Abstract The formation of thiadiazolidines 3a-c and dithiazolidines 4a-c and 5a-b from the title reactions has been studied in detail under a variety of conditions. On the basis of kinetic measurements, isomerization studies and cross experiments a mechanism is proposed involving path (b)(Scheme 1) as the first step, followed by a series of isomerizations as shown in Scheme 3.
