SYNTHESIS OF AN ESPERAMICIN CORE ANALOG WITH AN EPOXIDE TRIGGER

An esperamicin core analog 4 with an epoxide trigger like that found i n the related enediyne, dynemicin, was prepared. Surprisingly, it was found to be relatively stable; the p-aminophenyl substituent did not f acilitate epoxide solvolysis to the extent that had been anticipated. A mild acid, pyridinium p-toluenesulfonate, was found to induce solvol ysis of 4 and Icd to the formation of the cycloaromatized product 25. Copyright (C) 1996 Elsevier Science Ltd