Concomitant Dehydration and C-Acetylation of Tertiary Alcohols

Treatment of tertiary alcohols with HOAc-Ac_2O-HCLO_4 was found to afford C-acetylation products in good yield.1-Methylcyclohexanol 3 gave both exocyclic 5 and endocyclic 4 acetylation with a ration of about 2:1 as detected by the H-HMR spectrum of the mixture.This proportion may be dependent upon the initial direcftion of dehydration of tertiary alcohols.Only endocyclic product 4 was obtained with 1-methylcyclohexene 6 as the substrate.Methylene eyclohexane 7 under the same conditions afforded a mixture of exocyclic and endocyclic products in the ration of 8.5:1.5.