Indolocarbazoles. 1. Total synthesis and protein kinase inhibiting characteristics of compounds related to K-252c

The condensation of indolo[2,3-a]-carbazole (12) with 2,5-dimethoxytetrahydrofuran derivatives gave cyclofuranosylated compounds (e.g. 13), which were converted via dibromocompounds to the dinitriles (e.g. 25). Hydrolysis, hydrolysis-reduction and thiolysis afforded imides, lactams (e.g. 27) and their thio analogs. These compounds were potent inhibitors of the protein kinase C family.