Two homoallyl/cyclopropylalkyl rearrangements accompanying a Wolff-Kishnertype reduction

Conceived as a model study for the enantio selective synthesis of the natur al product (S)-bakuchiol, the deoxygenation of a recently described trishom oallyl alcohol was attempted using the Kabalka modification of the Wolff-Ki shner method after prior oxidation of the alcohol to the ketone. However, a n unprecedented succession of homoallyl/cyclopropyl ring closure and ring o pening altered the carbon skeleton profoundly. The crucial intermediates ar e assumed to be radicals although carbanions cannot yet be definitely ruled out. (C) 2001 Elsevier Science Ltd. All rights reserved.