Transannular hydride shifts; the solvolytic behaviour of bicyclo[3.3.2]-decan-3-exo-yl toluene-p-sulphonate

Abstract

Bicyclo[3.3.2]decan-3-exo-yl tosylate is extremely reactive in buffered acetolysis [k_rel(w.r.t. cyclohexyl) 9.0 × 10³], and gives bicyclo[3.3.2]dec-2-ene (94%) and the corresponding 3-acetates (6%) in the ratio exo:endo 5 : 1. Solvolysis of 2,2,3,4,4-pentadeuteriobicyclo[3.3.2]decan-3-exo-yl tosylate is accompanied by a C-7 → C-3 transannular hydride shift (48%). The latter result is to be contrasted with the much lesser extent of hydride shift in similar solvolysis of bicyclo[3.3.1]nonan-3-exo-yl tosylate.