INTRAMOLECULAR ADDITIONS OF ALLYLSILANES TO CONJUGATED DIENONES. TWO SYNTHESES OF (+/-)-EPI-WIDDROL.

Article abstract of DOI:10.1016/S0040-4020(01)87742-5

Two stereospecific total syntheses of epi-widdrol (1) are reported.The first synthesis features the cyclization of dienone 3a to construct bicyclic adduct 4a which is converted to epi-widdrol using conventional procedures.A second synthesis exploits the cyclization of dienone 17 to prepare functionalized bicyclo<5.4.0>undecene 18, which is converted to a known epi-widdrol precursor.