描述了子叶素 A 的收敛对映选择性全合成。通过我们实验室开发的催化不对称分子内环丙烷化制备的 A 环片段和由已知手性化合物通过修饰的酰基自由基环化制备的 C 环片段通过 Utimoto 偶联反应成功组装。通过钯介导的环化有效地构建了子叶素 A 的强大碳环八元环。支架中的所有羟基都被立体选择性地引入,并开发了一种改良的还原剂 Me4NBH(O2CiPr)3。糖部分片段是通过三个连续的碳氧键形成反应制备的,糖基化是使用万的方案完成的。
Cotylenol, one of the representative fusicoccane diterpenoids having 5-8-5-membered tricyclic carbon framework, is now synthesized for the first time via an eight-membered ring formation by an intramolecular ene reaction followed by an oxidative formation of the 8β,9α-glycol function on the central eight-membered ring.
Total synthesis of optically active cotylenol, a fungal metabolite having a leaf growth activity. Intramolecular ene reaction for an eight-membered ring formation
作者:Nobuo Kato、Hiroaki Okamoto、Hitoshi Takeshita
DOI:10.1016/s0040-4020(96)00059-2
日期:1996.3
Starting from condensation of two iridoid synthons, (3S,8R)-benzyloxy-1-iriden-7-al and (3R)-7-chloro-1-iridene, cotylenol, one of the representative fusicoccane diterpenoids having 5-8-5-membered tricyclic carbon framework, is now synthesized for the first time via an eight-membered ring formation by an intramolecular ene reaction and subsequent introduction of an alpha-hydroxyl group.
A convergent enantioselectivetotalsynthesis of cotylenin A is described. The A-ring fragment, prepared via the catalytic asym-metric intramolecular cyclopropanation developed in our laboratory, and the C-ring fragment, prepared from a known chiral compound via a modified acyl radical cyclization, were successfully assembled by the Utimoto coupling reaction. The formidable carbocyclic eight-membered
描述了子叶素 A 的收敛对映选择性全合成。通过我们实验室开发的催化不对称分子内环丙烷化制备的 A 环片段和由已知手性化合物通过修饰的酰基自由基环化制备的 C 环片段通过 Utimoto 偶联反应成功组装。通过钯介导的环化有效地构建了子叶素 A 的强大碳环八元环。支架中的所有羟基都被立体选择性地引入,并开发了一种改良的还原剂 Me4NBH(O2CiPr)3。糖部分片段是通过三个连续的碳氧键形成反应制备的,糖基化是使用万的方案完成的。
Correlation of cotylenol with the aglycone of fusicoccin