作者:Emile Bisagni、Marilys Rautureau
DOI:10.1055/s-1987-27864
日期:——
2-(3-Lithio-2-methoxy-4-pyridyl)-4,4-dimethyl-2-oxazoline (8) was condensed with aromatic aldehydes. Subsequent hydrolysis gave the corresponding lactones 10. Reduction by ammoniacal zinc or calalytic hydrogenation of these compounds over palladium yielded 3-arylmethyl-2-pyridone-4-carboxylic acids 11 which were transformed into 3-arylmethy1-4-acetyl-2-pyridones 12 by methyllithium. Acidic ring closure then easily led to (g)-fused 5-methyl-2H-isoquinoline-1-ones via a convergent pathway. This method is more rapid and convenient than former procedures reported for the synthesis of (g)-fused 5-methyl-1-functonalized isoquinolines.
2-(3-Lithio-2-methoxy-4-pyridyl)-4,4-dimethyl-2-oxazoline (8) 与芳香醛缩合。随后水解得到相应的内酯 10。这些化合物在钯上被氨化锌还原或热解氢化后得到 3-芳基甲基-2-吡啶酮-4-羧酸 11,这些酸在甲基锂的作用下转化为 3-芳基甲基 1-4-乙酰基-2-吡啶酮 12。酸性闭环随后很容易通过收敛途径生成(g)-融合的 5-甲基-2H-异喹啉-1-酮。与以前报道的合成 (g)-fused 5-甲基-1-酮化异喹啉的方法相比,这种方法更加快速和方便。