Studies on the syntheses of heterocyclic compounds. Part CCCII. Alternative total syntheses of (±)-nandinine, (±)-canadine, and berberine iodide

Mannich reaction of 1-(2-bromo-5-hydroxy-4-methoxybenzyl)-1,2,3,4-tetrahydro-6,7-methylenedioxyisoquinoline (IX) gave 12-bromonandinine (II) which was debrominated to afford (±)-nandinine (I). Methylation of (±)-nandinine with diazomethane gave (±)-canadine (III), dehydrogenation of which with iodine afforded berberine iodide (XI).