CuLi<sub>2</sub>Cl<sub>4</sub> catalysed cross-coupling strategy for the formal synthesis of the diterpenoid (+)-subersic acid from (–)-sclareol
作者:Qiangyong Wu、Peiqiang Wang、Bin Zhou、Sikai Hua、Jiangmeng Ren、Bu-Bing Zeng
DOI:10.3184/174751917x14967701766923
日期:2017.7
leading to the concise synthesis of (+)-subersic acid with an overall yield of 25.7% from commercially available (–)-sclareol. The coupled product 15-(2-methoxy-5-carbomethoxy)phenyl-labda-8(9),13E-diene was obtained in 62% yield under CuLi2Cl4 conditions starting from 2-iodo-4-carbomethoxyanisole and 15-acetoxy-labda-8(9),13E-diene. These were derived from 4-hydroxybenzoic acid and (–)-sclareol respectively
CuLi2Cl4 催化的区域选择性交叉偶联用于从市售 (-)-香紫苏醇以 25.7% 的总产率简明合成 (+)-辛二酸的关键步骤。在 CuLi2Cl4 条件下,以 2-iodo-4-carbomethoxyanisole 和 15-acetoxy-labda 为起始原料,以 62% 的收率获得了偶联产物 15-(2-甲氧基-5-碳甲氧基)苯基-labda-8(9),13E-二烯-8(9),13E-二烯。它们分别来自 4-羟基苯甲酸和 (-)-香紫苏醇。15-(2-甲氧基-5-碳甲氧基)苯基-labda-8(9),13E-二烯很容易通过苯酚醚和酯的去甲基化转化为(+)-辛二酸。这种交叉偶联策略显示出良好的官能团耐受性,并且以中等产率获得了各种 (+)-辛二酸衍生物。