螺环倍半萜(±)-α-花柏烯-3-酮的全合成

Total Synthesis of (±)-α-Chamigrene-3-one

通过萜品油烯 ( Terpinolene)与 2 ,4-二氧代戊酸甲酯的 de Mayo反应得到 [2 +2 ]光加成产物 ,经反aldol重排 ,再环合成具有螺 [5 ,5 ]十一烷结构的花柏烯基本碳架 ,进而对其官能团进行化学修饰 ,完成了螺环倍半萜 (± ) -α-花柏烯 -3 -酮的全合成 .

In this paper, (±)-α-chamigrene-3-one, a spiro-sesquiterpenoid isolated from Marchantia polymorpha, was synthesized via a useful synthon in the synthesis of chamigrene-type sesquiterpenes, i.e., 1,5,5-trimethyl-1-methoxycarbonylspiroundeca-1,8-dien-3-one(6). This precursor was obtained by the de Mayo reaction of terpinolene with methyl 2,4-dioxopentanoate, followed by the retro-aldol rearrangement of the proto- photocyclo-adducts and then Claisen condensation. The title compound was prepared via compound 6 by further transformed by chemical modification at the functional groups.