ON THE MECHANISM OF THE REARRANGEMENT OF 7-VINYLNORCARADIENES

Thermal rearrangement of diastereomeric 7-vinylnorcaradienes 2 and 3 r esulted in the formation of three products, two of which were derived from the vinylcyclopropane-cyclopentene rearrangement and the third fr om the Cope rearrangement. Almost identical product ratios from 2 and 3 suggested the existence of a common biradical as an intermediacy. Th e kinetic versus thermodynamic control of the rearrangement was achiev ed by the choice of the substituent (X) in norcaradienes 9. Copyright (C) 1996 Elsevier Science Ltd.