Quinoline alkaloids. Part 19. Synthesis of O-methylptelefolonium iodide and (±)-dubinidine
Abstract
The terminal olefin, O-methylptelefolonium iodide (5; X = I), was synthesised from the hydroxyisopropyldihydrofuroquinoline (4) by successive dehydration and methylation. Dehydration of the tertiary alcohol (9a) with triphenyl phosphite dibromide and then hydroxylation furnished (±)-dubinidine (8).