Notizen: Regiospecific Synthesis of 1,2-Dialkylthio-7(alkyl-or aryl)thiocycloheptatrienes and 1,2-Dialkylthio-7-alkoxycycloheptatrienes

Abstract

Hydride abstraction by trityl tetrafluoborate from a mixture of cyeloheptatriene[1,2]-and cycloheptatriene[3,4]-p-dithiine gave tropenylium[1,2]-p-dithiin tetrafluoborate. The latter was found to add either methoxide or various thiolates only at the tropenylium C-3, which constitutes the first entry to regiospecifically trifunctionalized cycloheptatrienes. In contrast, cycloheptatriene[1,7]-p-dithiine or various other cycloheptatrienes substituted at C-7 with either methylthio or t-butylthio groups were found to undergo alkylthiolate abstraction by trityl tetrafluoborate. This limits the usefulness of the above synthetic methods for polyfunctionalized cycloheptatrienes.