Graduate School of Pharmaceutical Sciences, The University of Tokyo, Hongo, Tokyo 113-0033, Japan.
Org Lett. 2013 Sep 6;15(17):4488-91. doi: 10.1021/ol402038b. Epub 2013 Aug 12.
The multiply oxygenated ABC-ring system of the dihydro-β-agarofurans was synthesized by employing two highly stereoselective reactions. The quinidine-catalyzed Diels-Alder reaction between a chiral dienophile and 3-hydroxy-4-methyl-2-pyrone simultaneously installed the C2-stereogenic center and two contiguous tetrasubstituted carbon centers (C5 and C10) of the A-ring. After 12 additional transformations, the aldol reaction of the resulting spiral AC-ring cyclized the B-ring with stereoselective introduction of the C7- and C8-centers.
通过采用两种高度立体选择性反应，合成了二氢-β-agarofuran 的多氧化 ABC-环系统。手性双烯和亲双烯体的奎宁催化 Diels-Alder 反应同时在 A 环中安装了 C2 手性中心和两个相邻的四取代碳原子中心（C5 和 C10）。经过 12 步额外的转化，所得螺旋 AC 环的羟醛反应以立体选择性的方式引入了 C7 和 C8 中心，从而使 B 环环化。
