Herein, we report the first enantioselective totalsynthesis of the highly complex hamigeran diterpenoid (−)-hamigeran F and its rearrangement product. The synthetic strategy features key steps of asymmetric hydrogenation, Horner–Wadsworth–Emmons olefination, and intramolecular Friedel–Crafts acylation to construct the [6,6,5]-tricyclic skeleton bearing three consecutive stereocenters, a sequence of
A series of proaromatic electron acceptors derived from fulvenes were synthesized from tetrachlorocyclopentadiene and previously unknown 1,4-dicyano- and 1,4-dialkoxycarbonyl-2,3-dimethoxy cyclopentadienes. Two reversible one-electron reductions steps observed for fulvalenes coalesce into one two-electron reduction step upon increasing the length of the conjugating bridge. (C) 2003 Elsevier Ltd. All rights reserved.