Abstract
Synthetic quests within the longifolane class of sesquiterpenes have included such elaborately bridged structures as longifolene,1 isolongifolene,2 and culmorin.3 The tetracyclic member of this interesting group of naturally occurring compounds; namely, longicyclene (1)4 has heretofore evaded synthesis. Longicyclene (1), isolated from turpentine oil of Pinus longifolia, was assigned structure 1 on the basis of spectral evidence and an acid-catalyzed conversion to longifolene.4,5 We wish to report herein a stereoselective total synthesis of (±)-longicyclene (1).