Brønsted Acid Mediated Cyclization of Enaminones. Rapid and Efficient Access to the Tetracyclic Framework of the <i>Strychnos</i> Alkaloids
作者:Rahul V. Edwankar、Chitra R. Edwankar、Ojas A. Namjoshi、Jeffrey R. Deschamps、James M. Cook
DOI:10.1021/np200759h
日期:2012.2.24
ma alkaloids is described. Enaminone 16, synthesized in high yield, has been cyclized under the influence of a Brønsted acid to provide the core tetracyclic framework 17 of the Strychnos alkaloids in optically active form or alternatively to the β-ketoester tetrahydro-β-carboline (THBC) unit 18, by varying the equivalents of acid and the molar concentration. Attempts to utilize 18 to form the C(7)–C(16)
其允许四环核心的快速施工高效的非对映选择性方法的开发17所述的马钱子-白坚木属生物碱进行说明。以高产率合成的烯胺酮16已在布朗斯台德酸的影响下环化,以提供旋光形式的马钱子生物碱的核心四环骨架17或替代 β-酮酯四氢-β-咔啉 (THBC) 单元18,通过改变酸的当量和摩尔浓度。尝试利用18形成以严格胺为代表的 akuammiline 相关生物碱的 C(7)–C(16) 键 ( 22),使用金属卡宾化学,也被描述。