Biomimetic synthesis of ascididemin and derivatives

Article abstract of DOI:10.1055/s-1994-25446

A two-step biomimetic synthesis of the pentacyclic pyrido[2,3,4- kl]acridine marine alkaloid ascididemin (3a) from quinolinequinone 5a and N- trifluoroacetamidokynuramine (4) is described. The crucial step (6 to 7) involves the simultaneous formation of two pyridine rings in a process which might well offer an explanation for the biogenetic synthesis in marine organisms. The preparation of substituted ascididemins by either starting from substituted quinolinequinones, e.g., 5b to afford 11-methoxyascididemin (3b), or by nitration of 3a to the mono 1- or 3-nitroascididemins (8 and 9 respectively) is reported.