Denieul M P, Laursen B, Hazell R, Skrydstrup T
Department of Chemistry, University of Aarhus, Langelandsgade 140, 8000 Aarhus C, Denmark.
J Org Chem. 2000 Sep 22;65(19):6052-60. doi: 10.1021/jo000750r.
Studies are reported on the use of either a 7-exo radical cyclization or an intramolecular Heck reaction as the key step for the construction of the benzophenone fragment of the PKC inhibitor, balanol. Whereas, the former approach was unsuccessful, the Heck reaction proved to be viable for the coupling of two fully functionalized aryl subunits affording regioselectively a biaryl seven-membered lactone with an exocyclic alkene as the major component, in contrast to the competing eight-membered ring lactone. Hydrolysis of the lactone followed by oxidative cleavage of the alkene with ruthenium tetraoxide completed this short synthesis of the benzophenone unit.
有研究报道了使用7-外向自由基环化反应或分子内Heck反应作为构建PKC抑制剂巴拉诺尔二苯甲酮片段的关键步骤。然而，前一种方法未成功，而Heck反应被证明对于两个完全官能化的芳基亚基的偶联是可行的，与竞争性的八元环内酯相比，该反应区域选择性地提供了以外环烯烃为主要成分的联芳基七元内酯。内酯水解后，用四氧化钌对烯烃进行氧化裂解，完成了二苯甲酮单元的这一简短合成。
