Abstract The H 2 SO 4-HOAc-Ac 2 O-catalysed dehydration of the epimeric 8a- methyldecahydronaphthalen-4a-ols has been shown to occur regiospecifically without skeletal or methyl migration, by loss of a proton syn to the departing anionic moiety. The results are interpreted in terms of the intermediacy of a tight ion pair where the oxy anion acts as the base in the removal of the proton. The introduction of an electron-withdrawing ...
