The relative and absolute configurations of L-755,807 were established through total synthesis. All four possible stereoisomers were prepared via a convergent synthetic strategy, including a novel diastereoselective Darzens reaction of an α-alkoxy aldehyde with di-tert-butyl bromomalonate, an E-selective Horner–Wadsworth–Emmons reaction, and late-stage coupling of the ring and side-chain segments. Additionally, biological evaluation of the synthesized compounds revealed their potent inhibitory activities (IC₅₀ = 5–21 μM) against amyloid-β aggregation for the treatment of Alzheimer's disease.

中文翻译：

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L-755,807的总合成，立体化学分配和生物学评估

L-755,807的相对和绝对构型是通过全合成建立的。所有四种可能的立体异构体均是通过聚合合成策略制备的，包括α-烷氧基醛与溴化丙二酸二叔丁酯的新型非对映选择性Darzens反应，E-选择性霍纳-沃兹沃思-埃蒙斯反应，以及酯的后期偶联。环和侧链段。此外，对合成化合物的生物学评估表明，它们 对淀粉样β聚集体具有有效的抑制活性（IC ₅₀ = 5–21μM），可用于治疗阿尔茨海默氏病。