作者:Takashi Matsumoto、Sachihiko Imai、Takashi Yoshinari、Shigeo Matsuno
DOI:10.1246/bcsj.59.3103
日期:1986.10
The conversion of racemic α-cyclocitral into 3-(3-isopropyl-4-methoxyphenethyl)-4,4-dimethyl-2-methylenecyclohexanone (2) was carried out in five steps via 3-(3-isopropyl-4-methoxyphenethyl)-2,4,4-trimethyl-1-cyclohexene. An intramolecular cyclization of 2 with polyphosphoric acid produced the corresponding two tricyclic ketones possessing cis- and trans-A/B ring junctions. Each of these ketones was further converted into 12-mesyloxy-9(10→20)-abeo-abieta-1(10),8,11,13-tetraene in four steps. The mesylate was reduced with lithium aluminium hydride to give (±)-pisiferin.
外消旋α-环柠檬醛通过 3-(3-异丙基-4-甲氧基苯乙基)-2,4,4-三甲基-1-环己烯分五个步骤转化为 3-(3-异丙基-4-甲氧基苯乙基)-4,4-二甲基-2-亚甲基环己酮(2)。2 与多磷酸的分子内环化反应产生了相应的两个三环酮,它们具有顺式和反式-A/B 环连接。这两个酮都在四个步骤中被进一步转化为 12-甲氧基-9(10→20)-阿贝奥-阿比埃塔-1(10),8,11,13-四烯。用氢化铝锂还原甲磺酸酯,得到 (±)-pisiferin 。