Treatment of secondary allylic chlorides or allylic phosphates in tetrahydrofuran with prenyl Grignard reagent in the presence of CuCN · 2 LiCl gave geraniol or farnesol derivatives with high SN2′ selectivity. Phosphate leaving groups were highly trans-stereoselective for the formation of (E,E)-farnesol derivatives. Furthermore, complete anti-SN2′ selectivity was observed in the alkylation of optically active allylic phosphates. The present method appears to be an excellent carbon-carbon coupling reaction with high regio-, (E)-, and enantioselectivity. Coenzyme Q10 (ubiquinone 10) was efficiently synthesized using this methodology.
用
烯丙基
氯化物或
烯丙基
磷酸酯在
四氢呋喃中与
烯丙基格林尼亚试剂及CuCN·2LiCl反应,可以高选择性地生成
香叶醇或
法尼醇衍
生物。
磷酸酯的离去基团在生成(E,E)-
法尼醇衍
生物时表现出高度的反式立体选择性。此外,在光学活性
烯丙基
磷酸酯的烷基化反应中观察到了完全的反SN2′选择性。该方法似乎是一种优秀的
碳-
碳偶联反应,具有高的区分选择性、(E)选择性和对映选择性。采用该方法有效合成了
辅酶Q10(
泛醌10)。