Studies on the Synthesis of Phlegmarine-Type <i>Lycopodium</i> Alkaloids: Enantioselective Synthesis of (−)-Cermizine B, (+)-Serratezomine E, and (+)-Luciduline
作者:Alexandre Pinto、Miriam Piccichè、Rosa Griera、Elies Molins、Joan Bosch、Mercedes Amat
DOI:10.1021/acs.joc.8b00983
日期:2018.8.3
The synthesis of the Lycopodium alkaloids, (−)-cermizine B, (+)-serratezomine E, and (+)-luciduline using phenylglycinol-derived tricyclic lactams as chiral scaffolds, is reported. The requisite lactams are prepared by a cyclocondensation reaction between (R)- or (S)-phenylglycinol and the substituted δ-keto ester 11, easily accessible from (R)-pulegone. The factors governing the stereoselectivity
据报道,使用苯基甘醇衍生的三环内酰胺作为手性支架,合成了Lycopodium生物碱,(-)-cermizine B,(+)-serratezomine E和(+)-luciduline。通过(R)-或(S)-苯基甘氨醇与取代的δ-酮酯11之间的环缩合反应制备所需的内酰胺,所述取代的δ-酮酯11可容易地从(R)-普来高酮中获得。讨论了控制这些环缩合反应的立体选择性的因素。从立体化学的观点来看,合成的关键步骤是烯丙基取代基立体选择性地修饰到(S)-2-(哌啶基)甲基部分,以及立体选择性地除去手性诱导剂以得到顺式-十氢喹啉。