Synthesis of ascomycin and FK 506 derivatives with modified effector domain

Article abstract of DOI:10.1016/S0040-4039(99)00629-2

Oxidation of the 22-hydrazone of ascomycin using manganese dioxide generates in situ the reactive 22-diazo intermediate, which decomposes to give ascomycin analogues with modified effector region. In dichloromethane several products are obtained, whereas in methanol a cyclopropane derivative is generated as the main product starting from the hydrazone of both ascomycin and FK 506.