Synthesis of immunostimulatory alpha-C-galactosylceramide glycolipids via Sonogashira coupling, asymmetric epoxidation, and trichloroacetimidate-mediated epoxide opening.

Stereocontrolled syntheses of α-C-GalCer (2) and its α-C-acetylenic analogue 6 were accomplished in high efficiency by a convergent construction strategy from 1-hexadecene and D-galactose. The key transformations include Sonogashira coupling, Sharpless asymmetric epoxidation, and Et2AlCl-catalyzed cyclization of an epoxytrichloroacetimidate to generate protected dihydrooxazine 21.

通过从1 -十六碳烯和D -半乳糖出发的汇聚式构建策略，高效地完成了α - C -半乳糖神经酰胺（2）及其α - C -炔类似物6的立体控制合成。关键的转化包括Sonogashira偶联、Sharpless不对称环氧化以及环氧三氯乙酰亚胺酯在Et₂AlCl催化下的环化以生成受保护的二氢恶嗪21。