Alvarez-Manzaneda Enrique, Chahboun Rachid, Cabrera Eduardo, Alvarez Esteban, Alvarez-Manzaneda Ramón, Meneses Ricardo, Es-Samti Hakima, Fernández Antonio
Departamento de Química Orgánica, Facultad de Ciencias, Universidad de Granada, 18071 Granada, Spain.
J Org Chem. 2009 May 1;74(9):3384-8. doi: 10.1021/jo900153y.
A very expedient and efficient new route toward taiwaniaquinoids, bearing the 4a-methyltetrahydrofluorene skeleton, is reported. Key steps are the intramolecular Friedel-Crafts alkylation of an aryldiene and the degradative oxidation of a methylenedioxy group; the latter process could also be utilized for building the 2-hydroxy-1,4-benzoquinone unit, which is frequently found in natural products. Utilizing this new methodology, (+/-)-dichroanone (7) (three steps, 77% overall yield) and (+/-)-taiwaniaquinone H (6) (four steps, 70% overall yield) have been synthesized from commercial alpha- (11a) or beta-cyclocitral (11b).
报道了一种通往具有4a-甲基四氢芴骨架的台湾醌类化合物的非常便捷且高效的新路线。关键步骤是芳基二烯的分子内傅克烷基化反应以及亚甲基二氧基的降解氧化反应；后一过程也可用于构建天然产物中常见的2-羟基-1,4-苯醌单元。利用这种新方法，已从市售的α-(11a)或β-环柠檬醛(11b)合成了(±)-二氢异色满酮(7)(三步，总产率77%)和(±)-台湾醌H(6)(四步，总产率70%)。
