Toward a Total Synthesis of Okilactomycin. 1. A Direct, Enantiocontrolled Route to the Western Sector
作者:Leo A. Paquette、Serge L. Boulet
DOI:10.1055/s-2002-28510
日期:——
A synthesis of the western half of the macrocyclic ring framework of the antitumor antibiotic okilactomycin is described. The strategy employed rests on an efficient synthesis of meso-2,4-dimethylglutaric anhydride and ensuing resolution via reaction with (S)-(-)-α-methylbenzylamine, diborane reduction, and selective crystallization. Following acid-catalyzed cyclization to (2S,4R)-2,4-dimethyl-6-valerolactone
描述了抗肿瘤抗生素奥乳霉素大环框架西半部的合成。所采用的策略依赖于内消旋-2,4-二甲基戊二酸酐的有效合成,并通过与 (S)-(-)-α-甲基苄胺反应、乙硼烷还原和选择性结晶进行拆分。在酸催化环化为 (2S,4R)-2,4-dimethyl-6-valerolactone 后,采用无环立体控制策略通过适当结合功能来实现链延长。在模型反应序列中,敏感的醛 2 被进一步同源化为 β-酮酯 17,以模拟其最终预计与 3 的耦合。