CYCLIZATION AND REARRANGEMENTS OF FARNESOL AND NEROLIDOL STEREOISOMERS IN SUPERACIDS

Acid-catalyzed cyclization of 2,3-trans- and 2,3-cis-farensol proceeds regioselectively and stereospecifically, yielding drimenol and epi-drimenol, respectively. The trans and cis isomers of nerolidol undergo carbo- and heterocyclization reactions. The trans isomer gives tricyclic caged hydrocarbons with new skeletal types, while the rearrangements of the cis isomer produce derivatives of 2-oxabicyclo-[4.4.0]decane. The ICAR computer program was used to derive reasonable mechanisms for the acid-catalyzed transformations of nerolidol, and the probability of the mechanisms was evaluated by the molecular mechanics method.