Decahydroquinoline Ring <sup>13</sup>C NMR Spectroscopic Patterns for the Stereochemical Elucidation of Phlegmarine-Type <i>Lycopodium</i> Alkaloids: Synthesis of (−)-Serralongamine A and Structural Reassignment and Synthesis of (−)-Huperzine K and (−)-Huperzine M (Lycoposerramine Y)
作者:Caroline Bosch、Ben Bradshaw、Josep Bonjoch
DOI:10.1021/acs.jnatprod.9b00071
日期:2019.6.28
lycoposerramine Y and, hence, also implied the configurational reassignment of the latter. The revised structures of the above alkaloids were confirmed by enantioselective total synthesis. Additionally, the synthesis of (-)-serralongamine A via a common intermediate precursor is reported.
对石蒜碱生物碱的化石棉亚群的13 C NMR光谱数据进行分析后发现,光谱图谱可确定十氢喹啉核心中四个立体异构碳的立体化学排列。据报道,相对简单的化学位移组合预测集,为富勒麻碱型生物碱的立体化学分配提供了挑战。根据其NMR光谱图的化学变化,正式报告为顺式衍生物的生物碱石杉碱K和石杉碱M在结构上被重新指定为反式十氢喹啉。石杉碱M的NMR光谱数据与lyposeposerramine Y报道的数据相同,因此也暗示了后者的构型重新分配。通过对映选择性的全合成证实了上述生物碱的修饰结构。另外,报告了通过共同的中间体前体合成(-)-serralongamineA。