FACILE SYNTHESIS OF A SIMPLIFIED BICYCLO[7.3.1] ESPERAMICIN-CALICHEAMICIN ENEDIYNE CORE

An efficient non cobalt mediated route for the synthesis of a simplifi ed bicycle [7.3.1]enediyne core of the naturally occurring calicheamic ins and esperamicins is described. The key cyclization provides a sing le propargylic alcohol stereoisomer which is in the same relative conf iguration as that found in the naturally occurring calicheamicins and esperamicins. Selective functionalizations of the cyclized core via se lenium dioxide oxidations are described. Installation of an enone chem ical trigger provides a hydroxylated analog of a previously described biologically active synthetic enediyne.