The 9-decalyl and related cations. III. Generation of the 8-hydrindyl cation by solvolysis

Abstract

Acetolysis of 4-(cyclopent-1'-enyl)butyl and 3-(2'-methylenecyclopentyl)propyl derivatives, but not 3-(cyclohex-1'-enyl)propyl and 2-(2'-methylenecyclohexyl)ethyl derivatives, occurs with π-bond participation (95 and 92%, respectively) to give similar, including maybe identical, cationic species involving the 8-hydrindyl cation. On the basis of product composition, the 8-hydrindyl cations when generated from spiro[4,4]non-1-yl (σ-route) and cis- and trans-8-hydrindyl derivatives (direct route) are each different and are in turn different to those generated by the above π-routes. Reasons for the differences are discussed and the possible role of the counter-ion in ion-pairs is examined.