SULFUR AND THE ENEDIYNE ANTIBIOTICS

Some of our studies in the area of the enediyne antibiotics are discussed, with particular emphasis on the involvement of sulfur in these compounds. First, a model study for the ABC-ring system of the calicheamicin gamma1I oligosaccharide involving a [3,3]-sigmatropic rearrangement is described which enabled the stereoselective installation of the 4-thio substituent on the B-ring and which served as the cornerstone for the first synthesis of the entire oligosaccharide fragment. The first enantioselective synthesis of (-)-calicheamicinone is then described. Finally, a novel triggering device for a dynemicin mimic based upon a 2-(phenylsulfonyl)ethyl carbamate is described which led to the synthesis of an extremely potent antitumor agent.