Department of Chemistry and Biochemistry, University of California at Santa Barbara, Santa Barbara, California 93106-9510, United States.
Org Lett. 2011 Jan 7;13(1):118-21. doi: 10.1021/ol102652t. Epub 2010 Dec 7.
A formal synthesis of berkelic acid is reported. The strategy employs the combination of a chiral exocyclic enol ether and an achiral isochromanone to afford the chroman spiroketal core via a base-triggered generation and cycloaddition of an o-quinone methide intermediate. Other key steps include equilibration of the spiroketal, intramolecular benzylic oxidation, and lactone addition/hemiketal reduction; all occur with good diastereoselectivity.
本文报道了 berkelic 酸的一种全新合成方法。该策略采用手性外环己烯醇醚与非手性异色满酮的组合，通过碱触发的邻醌甲醚中间体的生成和环加成反应，构建了色满螺缩酮核心。其他关键步骤包括螺缩酮的平衡、分子内苄基氧化和内酯加成/半缩酮还原；所有这些反应都具有良好的非对映选择性。
