Synthesis of the Marine Alkaloid Cylindricine C and Serendipitous Synthesis of Its 2,13-Di-<i>epi</i> Stereoisomer
作者:Arnaud Pastor、Rohen Prinsloo、Kristen N. Burford、Andrew R. Macdonald、Masood Parvez、Chris Gendy、Thomas G. Back
DOI:10.1021/acs.joc.3c01467
日期:2023.10.6
A new approach to the marine alkaloid cylindricine C afforded its previously unreported (±)-2,13-di-epi stereoisomer as the major product along with a minor amount of the racemic parent alkaloid. Key steps included a stereoselective dianion alkylation of a monoester of 1,2-cyclohexanedicarboxylic acid and an annulation based on the tandem conjugate addition of a primary amine to an acetylenic sulfone
海洋生物碱 cylindricine C 的新方法提供了其先前未报道的 (±)-2,13-di- epi立体异构体作为主要产物以及少量的外消旋母体生物碱。关键步骤包括 1,2-环己烷二甲酸单酯的立体选择性双阴离子烷基化,以及基于伯胺与炔属砜的串联共轭加成的环化,然后对所得砜稳定的碳负离子进行分子内酰化。由此形成的顺式氮杂萘烷部分,包含产物的环己烷A环和烯胺酮B环,通过硒基氯诱导侧丁烯基取代基与烯胺酮部分的环官能化,然后进行硒代-Pummerer反应,进一步精制而成。脱磺酰化和烯胺酮还原得到最终产物。分子建模和 X 射线晶体学提供了对这些过程的进一步了解。