Reactions of Sulfanyl Chlorides with Thiocamphor and Thiofenchone: <i>Wagner</i><i>Meerwein</i> Rearrangement of an Intermediate Thiocarbonylium Ion

Abstract

Abstract The reaction of sulfanyl and disulfanyl chlorides with thiocamphor ( 6 ) in the presence of Et 3 N leads to unsymmetrical di‐ and trisulfanes, respectively ( Schemes 2 and 4 ). A reaction mechanism via a thiocarbonylium ion, which is immediately deprotonated, is proposed. The formation of a minor product 10 in the absence of a base, resulting from a Wagner  Meerwein rearrangement, is an additional evidence for the intermediacy of a thiocarbonylium ion ( Scheme 3 ). On the other hand, the non‐enolizable thiofenchone ( 13 ) reacts with sulfanyl chlorides in CH 2 Cl 2 /Et 3 N to give exclusively products with a rearranged bicyclic skeleton ( Scheme 5 ). A WagnerMeerwein rearrangement of the intermediate thiocarbonylium ion is the key step. The structures of the products 10 and 14 , which have rearranged bicyclic systems, have been established by X‐ray crystallography.