A1,3-strain enabled retention of chirality during bis-cyclization of β-ketoamides: total synthesis of (−)-salinosporamide A and (−)-homosalinosporamide A
摘要:
本文介绍了一种简明的对映体选择性合成 I 期抗癌剂 (â)-salinosporamide A 的方法。所描述策略的简洁性源于δ-酮三级酰胺的关键双环化,这种双环化是在克级规模上完成的,通过A1,3-应变保持了光学纯度,使得外延化相对于双环化的速度较慢。(â)-homosalinosporamide A 的合成证明了该策略在衍生物合成方面的多功能性。
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
A1,3-strain enabled retention of chirality during bis-cyclization of β-ketoamides: total synthesis of (−)-salinosporamide A and (−)-homosalinosporamide A
作者:Henry Nguyen、Gil Ma、Daniel Romo
DOI:10.1039/c0cc00607f
日期:——
A concise, enantioselective synthesis of the Phase I anticancer agent, (â)-salinosporamide A, is described. The brevity of the described strategy stems from a key bis-cyclization of a β-keto tertiary amide, accomplished on gram scale, which retains optical purity enabled by A1,3-strain rendering epimerization slow relative to the rate of bis-cyclization. The versatility of the strategy for derivative synthesis is demonstrated by the synthesis of (â)-homosalinosporamide A.
本文介绍了一种简明的对映体选择性合成 I 期抗癌剂 (â)-salinosporamide A 的方法。所描述策略的简洁性源于δ-酮三级酰胺的关键双环化,这种双环化是在克级规模上完成的,通过A1,3-应变保持了光学纯度,使得外延化相对于双环化的速度较慢。(â)-homosalinosporamide A 的合成证明了该策略在衍生物合成方面的多功能性。