Department of Chemistry and Biochemistry, University of California-Los Angeles , 607 Charles E. Young Drive East, Los Angeles, California 90095-1569, United States.
J Am Chem Soc. 2018 Jan 31;140(4):1280-1284. doi: 10.1021/jacs.7b13591. Epub 2018 Jan 19.
An asymmetric synthesis of (-)-callyspongiolide is described. The route builds the macrolide domain atypically from a disaccharide and a monoterpene without passing through a seco-acid. Chiral iridium catalysis selectively joins fragments. Subsequent degradation of an imbedded butyrolactone via perhemiketal fragmentation affords a stereo- and regio-defined homoallylic alcohol that is engaged directly in a carbonylative macrolactonization. Further elaboration of the polyunsaturated appendage provides the natural product in a particularly direct and flexible manner.
描述了（-）-卡利色醇的不对称合成。该路线非典型地从二糖和单萜构建大环内酯，而不经过脱羧酸。手性铱催化选择性地连接片段。随后通过过氧缩酮断裂降解一个嵌入的丁内酯，得到立体和区域定义的偕丙醇，该醇直接参与羰基化大环内酯化反应。进一步修饰多不饱和侧链以特别直接和灵活的方式提供了天然产物。
