Synthesis of enantiopure mono- and disubstituted tetrahydroisoquinolines by 6-exo radical cyclizations
作者:Rafael Pedrosa、Celia Andrés、Jesús M Iglesias、Manuel A Obeso
DOI:10.1016/s0040-4020(01)00274-5
日期:2001.4
menthol, readily cyclized stereoselectively by reaction with tributyltin hydride in the presence of AIBN. The cyclization compounds were transformed into enantiopure 4-alkyl tetrahydroisoquinolines by reductive ring opening of the N,O-acetal moiety with lithium aluminum hydride. Enantiopure 1,4- and 3,4-dialkyl-substituted tetrahydroisoquinolines were also prepared by reaction of the cyclized compounds
由(-)-8-氨基薄荷醇衍生的2-(邻溴苯基)-3-烯丙基和2-烯丙基-3-(邻溴苄基)取代的全氢苯并恶嗪易于在存在下与氢化三丁基锡反应而立体选择性地环化AIBN。通过用氢化铝锂还原N,O-乙缩醛部分的开环,将环化化合物转化为对映体纯的4-烷基四氢异喹啉。对映体纯的1,4-和3,4-二烷基取代的四氢异喹啉还可以通过环化的化合物与甲基碘化镁反应,然后消除薄荷醇附肢而制备。