ENANTIOSELECTIVE WITTIG RING CONTRACTION INDUCED BY CHIRAL BASES. THE TOTAL SYNTHESIS AND ABSOLUTE CONFIGURATION OF (+)-ARISTOLACTONE

Article abstract of DOI:10.1016/S0040-4039(00)95502-3

<2,3> Wittig ring contraction of the achiral 13-membered acetylenic ether 1 via treatment with lithio (R,R) or (S,S)-bis-(1-phenylethyl)amide afforded the (R)-(+) or (S)-(-)-propargylic alcohol (+)-2 or (-)-2, respectively, of >60percent ee in 75percent yield.