Studies directed towards the total synthesis of narbonolide: stereoselective synthesis of the C1–C15 chain

A stereoselective synthesis of the C1–C15 chain of narbonolide, a 14-membered macrolactone belonging to the pikromycin family of antibiotics is described. The key steps involved in this synthesis are desymmetrization of bicyclic olefin with Brown’s asymmetric hydroboration, Evans aldol reaction, Takai olefination and Yamaguchi esterification to yield the corresponding ester.