Rearrangement and trans-Elimination contrary to the Chugaev Reaction Rule. VIII. Thermal Rearrangement of 2-Alkenyl S-Alkyl Xanthate

Abstract

In general, S-alkyl xanthates of 2-alkenol thermally rearranged to the dithiolcarbonates accompanying allylic shift. When a mixture of two xanthates having different S-alkyl and O-alkenyl groups is allowed to rearrange thermally, no crossover products are obtained. A pair of position isomers did not transform to a same product, but to isomeric products with allylic shift respectively. 3-Aryl-substituted allylic xanthates, on the other hand, rearrange to the corresponding dithiolcarbonates without allylic shift. On the basis of these findings, mechanisms of the transformations are discussed.