Department of Chemistry, Chonnam National University, Gwangju 61186, Korea.
J Org Chem. 2023 Feb 17;88(4):2605-2611. doi: 10.1021/acs.joc.2c02711. Epub 2023 Feb 1.
Concise syntheses of naturally occurring γ-butenolides (+)-xylogiblactones B and C have been achieved for the first time starting from commercial methyl crotonate in 5-8 steps. The synthetic course involves allenoate γ-addition to racemic aldehydes through a kinetic resolution to establish the required stereochemical framework as center and axial chirality and subsequent oxacyclization via gold catalysis to complete the (+)-xylogiblactone skeleton. Both key transformations proceed in a regio- and stereospecific manner. This outcome relies on finding an efficient synthetic method for racemic aldehydes as precursors for the kinetic resolution. Completion of the synthesis provides stereochemical clarification for (+)-xylogiblactones B and C.
首次以商业甲基巴豆酸酯为原料，经 5-8 步反应，简洁地合成了天然存在的γ-丁烯内酯（+）-木罗烯内酯 B 和 C。该合成路线包括通过动力学拆分，在手性中心和轴向手性的立体化学框架建立过程中，将丙炔酸盐γ-添加到手性醛，随后通过金催化进行氧杂环化，完成（+）-木罗烯内酯骨架。两个关键转化均具有区域和立体特异性。这一结果依赖于找到一种有效的合成方法来制备手性醛，作为动力学拆分的前体。该合成的完成提供了（+）-木罗烯内酯 B 和 C 的立体化学澄清。
