Modified Fry Cyanation of a Chiral Pyridinium Salt: Asymmetric Syntheses of (-)-Coniine and (-)-Solenopsin A
作者:Van Ha Vu、Laurie-Anne Jouanno、Adèle Cheignon、Thierry Roisnel、Vincent Dorcet、Sourisak Sinbandhit、Jean-Pierre Hurvois
DOI:10.1002/ejoc.201300595
日期:2013.8
The synthesis of chiral 2-cyano-Δ4-tetrahydropyridine 5 was carried out in 85 % yield through a modified two-step Fry reductive cyanation of pyridinium salt (+)-3c that used lithium triethylborohydride as the hydride donor. An alkylation–reduction sequence provided 2-alkyl-substituted tetrahydropyridines (+)-10a and (+)-10b in 72–75 % yield after chromatographic purification. This protocol has been
通过使用三乙基硼氢化锂作为氢化物供体的吡啶鎓盐 (+)-3c 的改进的两步 Fry 还原氰化反应,以 85% 的产率合成了手性 2-氰基-Δ4-四氢吡啶 5。烷基化-还原序列在色谱纯化后以 72-75% 的产率提供了 2-烷基取代的四氢吡啶 (+)-10a 和 (+)-10b。该协议已应用于哌啶生物碱 (-)-coniine 和 (-)-solenopsin A 的不对称合成。