Thalmine (1) and thalicberine (2a) are bisbenzylisoquinoline alkaloids which have been isolated from Thalictrum species.112 0-Methylthalicberine (2b) ( = thalmidinel) also occurs naturally.2 We undertook the synthesis of compound (3a) since on oxidation it might give thalmine and a compound containing the thalicberine skeleton by processes of intra- molecular radical coupling. Methylation of these possible products would give 0-methylthalmine and 0- ...
