7,8-Disubstituted 1-Benzylisoquinoline関連化合物の合成研究 その3 dl-Cularicineの合成

抄録

Bischler-Napieralski reaction of the phenolic bromo-amide (VII), which was prepared by the condensation of 4-benzyloxy-2-bromo-5-hydroxyphenethylamine (V) with methyl 2-bromo-4, 5-methylenedioxyphenylacetate (VI) and reduction with NaBH₄ of the resultant benzyldihydroisoquinoline (VIII) gave 7-benzyloxy-5-bromo-1-(2-bromo-4, 5-methylenedioxybenzyl)-8-hydroxy-1, 2, 3, 4-tetrahydroisoquinoline (IX). N-Methylation of IX gave X. The Ullmann reaction of X in the presence of potassium carbonate and cupric oxide in pyridine gave 6-benzyloxy-4-bromo-1-methyl-9, 10-methylenedioxy-1, 2, 3, 12, 12a-pentahydrobenzoxepino [2, 3, 4-i, j] isoquinoline (XI). Subsequent debromination of XI with LiAlH₄ gave XII and debenzylation of XII with hydrogen over 10% palladiumcharcol gave dl-cularicine (I). I was identified with natural cularicine by infrared and nuclear magnetic resonance spectral comparisons.