An approach to the synthesis of sinomenine
Abstract
The modified Pschorr reaction of 1-(2-amino-4,5-dimethoxybenzyl)-6-benzyloxy-1,2,3,4-tetrahydro-7-methoxy-2-methylisoquinoline (VIII) gave (±)-benzylpredicentrine (X), (±)-predicentrine (XI), and morphinandienone (XII). The (±)-predicentrine (XI) was also obtained by treatment of (X) with acid. Debenzylation of the morphinandienone (XII) afforded a diketone (IV), which had the same basic structure as a precursor (V) in the biogenesis of the sinomenine (I) proposed by Barton.