An unusual replacement of a methylene moiety by a phenylseleno group. Synthesis of mitomycin C labelled at C-6 by 13CH3 and C2H3

A novel replacement of the C-6-methylene group of 7,7-ethylenedioxy-6-methylenemitosane by a phenylseleno group was employed to prepare a critical intermediate in the synthesis of mitomycin C labelled at C-6 by 13CH3 and C2H3.