Graduate School of Pharmaceutical Sciences, Kyoto University, Sakyo-ku, Kyoto 606-8501, Japan.
J Org Chem. 2011 Jul 1;76(13):5506-12. doi: 10.1021/jo2008324. Epub 2011 Jun 8.
Asymmetric formal synthesis of (+)-lysergic acid was achieved with a reductive ring-opening reaction of chiral 2-alkynyl-3-indolyloxirane with NaBH(3)CN as the key step. With Zn(OTf)(2) as an additive, the ring-opening reaction proceeded regioselectively at the 3-position to give the corresponding propargyl alcohol, which was a precursor of the allenic amide for palladium-catalyzed domino cyclization to construct the ergot alkaloid core structure.
通过手性 2-炔基-3-吲哚环氧乙烷与 NaBH(3)CN 的还原开环反应,实现了 (+)-麦角酸的不对称全合成,该反应是关键步骤。在 Zn(OTf)(2)作为添加剂的条件下,开环反应在 3 位进行区域选择性反应,得到相应的炔丙醇,这是钯催化的串联环化反应构建麦角生物碱核心结构的烯丙酰胺前体。