Studies on the Synthesis of the Antitumor Agents Esperamicin A1/Calicheamicin γ1: Stereospecific Synthesis of the 12β-HydroxybicycloDiynene Core Structure via a Co2(CO)6-Acetylene-Mediated Synclinal Aldol Reaction

Article abstract of DOI:10.1021/jo00293a009

Treatment of 11 with n-Bu2BOTf/amine bases resulted in its stereospecific conversion into the 12β-hydroxybicyclo<7.3.1>diynene-Co2(CO)6 adduct 16.