The present invention provides a concise synthetic method for generating lactam-fused beta-lactones that feature, in some embodiments, a tertiary fused carbinol, quaternary carbons, and a reactive beta-lactone moiety available for further reactions. The present invention further provides compounds synthesized by this method as well as methods of using these compounds as inhibitors of the proteasome and fatty acid synthase.
Bioinspired Total Synthesis and Human Proteasome Inhibitory Activity of (−)-Salinosporamide A, (−)-Homosalinosporamide A, and Derivatives Obtained via Organonucleophile Promoted Bis-cyclizations
bis-cyclization of a β-keto tertiary amide, which retains optical purity enabled by A1,3-strain rendering slow epimerization relative to the rate of bis-cyclization. Optimization studies of the key bis-cyclization, enabled through byproduct isolation and characterization, are described that ultimately allowed for a gram scale synthesis of a versatile bicyclic core structure with a high degree of stereoretention
受生物合成考虑的启发,描述了抗癌剂 (−)-salinosporamide A 及其衍生物(包括 (−)-homosalinosporamide)的简明、对映选择性合成的完整说明。合成策略的简洁性源于 β-酮叔酰胺的关键双环化,它保留了由 A 1,3菌株实现的光学纯度,从而相对于双环化速率呈现缓慢的差向异构化。描述了通过副产物分离和表征实现的关键双环化的优化研究,最终实现了具有高度立体保留的通用双环核心结构的克级合成。通过 Knochel 方法生成锌酸盐的优化程序通常用于合成 salino A 衍生物,导致侧链连接的显着改善和 salino A 的新型非对映异构体。合成证明了所述策略的多功能性设计的衍生物包括 (−)-homosalinosporamide A。还报道了使用酶法测定这些衍生物对人 20S 和 26S 蛋白酶体的抑制。所描述的盐A全合成提出了有趣的问题,即生物合成酶如何通过光