Department of Chemistry and Biochemistry, University of Delaware, Newark, Delaware 19716, USA.
J Org Chem. 2013 Sep 6;78(17):8437-41. doi: 10.1021/jo401158d. Epub 2013 Aug 6.
Organocatalyzed enantioselective allylation of 2-iodocyclohexenone followed by methylation and oxy-Cope rearrangement delivered enantiomerically enriched 2-methyl 3-allyl cyclohexanone, which engaged in acid-catalyzed Robinson annulation to give the bicyclic enone. Subsequent elaboration of the pendant allyl group into an α-diazo β-keto ester set the stage for Rh-mediated cyclization to deliver the tricyclic A-B-C core of the Veratrum alkaloids.
有机催化的对映选择性烯丙基化 2-碘环己酮，然后进行甲基化和氧-Cope 重排，得到对映体富集的 2-甲基 3-烯丙基环己酮，该酮与酸催化的 Robinson 环化反应，得到双环烯酮。随后将侧链烯丙基基团进一步转化为α-重氮β-酮酯，为 Rh 介导的环化反应奠定了基础，从而得到藜芦生物碱的三环 A-B-C 核心。
