作者:A. Paul Krapcho、Timothy P. Gilmor
DOI:10.1002/jhet.5570350328
日期:1998.5
Aromatizations of 7a, 7b led to the corresponding pyridine esters 8a, 8b which on reduction with lithium aluminum hydride yielded the corresponding carbinols 9a, 9b. Oxidation of 9a, 9b by manganese dioxide afforded aldehydes 6e, 6f. Aldehydes 6a-f were readily converted into the benz[g]isoquinolines 10a-f on heating in polyphosphoric acid.
苄基锌试剂以较高的区域选择性加入衍生自吡啶-3-羧甲醛(1a)或3-乙酰吡啶(1b)的1-(苯氧羰基)盐,生成1-(苯氧羰基)-4-苄基-1,4-二氢吡啶-3 -羧醛5a,5c或酮5b,5d。这些二氢类似物与硫的芳香化反应导致相应的醛6a,6c或酮6b,6d。醛前体的另一合成涉及将苄基锌试剂添加到由烟碱甲酯形成的1-(苯氧羰基)盐中,这导致相应的1-(苯氧羰基)-4-苄基-1,4-二氢烟碱甲酯7a,7b。7a,7b的芳香化生成相应的吡啶酯8a,8b,然后将其用氢化铝锂还原,得到相应的甲醇9a,9b。用二氧化锰氧化9a,9b得到醛6e,6f。在多磷酸中加热时,醛6a-f容易转化为苯并[ g ]异喹啉10a-f。