Synthetic Strategy for the Coupling of the Calicheamicin Oligosaccharide with Aglycons: Synthesis of Dynemicin A‐Calicheamicin Hybrid Structures

An enediyne unit, an epoxide ring, and other functional groups characterize the aglycon moiety of 1. Compound 1 was synthesized stereoselectively by Schmidt coupling of the corresponding enediyne bridgehead alcohol after it had been converted into the hydroxyethyl compound by treatment with the trichloroacetimidate of the sugar moiety. The required reactions are tolerated by the highly sensitive functional groups in the molecule. This work brings the total synthesis of enediyne antibiotics one step closer.