The Reactions of Selected Terpene Alcohols with Acetonitrile in the Presence of Boron Trifluoride Etherate

Aseries of thirteen terpene alcohols 1-13 of bornane, fenchane and isotricyclene systems was subjected to the reaction with acetonitrile in the presence of BF3_Et2O as a catalyst to give respective acetamides and/or alkenes. The use of boron trifluoride etherate instead of the usually applied protonic donors let us establish beyond any doubt the carbonium ion stage participation. The assumed reaction course was corroborated by cationic Wagner-Meerwein, Namietkin and homoallylic rearrangements observed during studies under investigation. Simultaneously no evidence for the imidate formation was found. Such a mode of the reaction mechanism was alternatively suggested earlier by Sjöberg [9] for the reaction of sec- and tert-butanol with acetonitrile in the presence of boron trifluoride etherate.