Studies in macrolide synthesis: A concise asymmetric synthesis of a macrolide intermediate for the erythronolides.
作者:Ian Paterson、David D.P. Laffan、David J. Rawson
DOI:10.1016/s0040-4039(00)80325-1
日期:1988.1
The enantiomerically-pure 14-membered ring macrolide 1 is prepared in 14 steps from the racemic aldehyde 4, Z=SPh. The C2-C4 and C8-C10 stereorelationships in 1 are controlled in a single step by an Evans aldol condensation with (±)-4. Macrolactonisation, 23 → 1, takes place in high yield (91%).
Kinetic resolution of racemic allylic alcohols <i>via</i> iridium-catalyzed asymmetric hydrogenation: scope, synthetic applications and insight into the origin of selectivity
作者:Haibo Wu、Cristiana Margarita、Jira Jongcharoenkamol、Mark D. Nolan、Thishana Singh、Pher G. Andersson
DOI:10.1039/d0sc05276k
日期:——
Asymmetric hydrogenation is one of the most commonly used tools in organic synthesis, whereas, kineticresolution via asymmetric hydrogenation is less developed. Herein, we describe the first iridium catalyzed kineticresolution of a wide range of trisubstituted secondary and tertiary allylic alcohols. Large selectivity factors were observed in most cases (s up to 211), providing the unreacted starting
不对称氢化是有机合成中最常用的工具之一,而通过不对称氢化进行动力学拆分的开发较少。在此,我们描述了各种三取代仲和叔烯丙醇的第一次铱催化动力学拆分。在大多数情况下观察到较大的选择性因子(高达211),从而以良好的收率和高水平的对映体纯度(ee 高达 >99%)提供未反应的起始材料。该方法的实用性在一些生物活性天然产物的对映选择性正式合成中得到了强调,包括 pumiliotoxin A、inthomycin A 和 B。提出了 DFT 研究和关于选择性起源的选择性模型。