Studies on the syntheses of heterocyclic compounds. Part CDLXII. Total photolytic syntheses of aporphine [(±)-N-methyl-laurotetanine, (±)-cassythicine, and (±)-pukateine], proaporphine [(±)-orientalinone], and morphinandienone [(±)-pallidine and (±)-salutaridine] alkaloids

Abstract

Total syntheses of some aporphine, proaporphine, and morphinandienone alkaloids by photolysis of phenolic bromoisoquinolines are described. The 8-bromo-1-(3-hydroxybenzyl)isoquinolines (34), (35), and (36) gave the aporphine alkaloids (±)-cassythicine (40), and (±)-pukateine (43), and (±)-N-methyl-laurotetanine (42), respectively. The 8-bromo-1 -(4-hydroxybenzyl)isoquinoline (37) afforded the proaporphine alkaloid (±)-orientalinone (46). The 1-(2-bromobenzyl)-7-hydroxyisoquinoline (39) gave the morphinandienone alkaloid (±)-salutaridine (49). The photolysis of 8-bromo-1-(2-bromo-5-hydroxy-4-methoxybenzyl)-1,2,3,4-tetrahydro-7-hydroxy-6-methoxy-2-methylisoquinoline (38) gave an abnormal product, (±)-pallidine (48).