Synthesis of coruscanones A and B, metabolites of Piper coruscans, and related compounds
作者:O. P. Shestak、V. L. Novikov
DOI:10.1007/s11172-010-0048-9
日期:2010.1
Base-catalyzed rearrangements of both individual 4-(acylmethylidene)butenolides and their mixtures prepared by condensation of citraconic anhydride with various phosphoranes occur successfully only in the presence of 5.2% MeONa in MeOH (molar ratio MeONa: substrate ≤ 10: 1, room temperature, 1–2 h). Under these conditions, the yields of 2-cinnamoyl-4-methylcyclopent-4-ene-1,3-dione (coruscanone B)
单独的 4-(酰基亚甲基)丁烯内酯及其混合物的碱催化重排仅在 MeOH 中存在 5.2% MeONa(摩尔比 MeONa: 底物 ≤ 10: 1,室温)时成功发生, 1-2 小时)。在这些条件下,2-cinnamoyl-4-methylcyclopent-4-ene-1,3-dione (coruscanone B) 和 2-acetyl-4-methylcyclopent-4-ene-1,3-dione 的产率分别为 56 和 65 %, 分别。随着反应温度或 MeONa: 底物摩尔比的显着增加,将 MeOH 正式添加到这些三酮的 C(4)=C(5) 双键成为一个可观的(或主要的)过程。Coruscanone B 与 CH2N2 在乙醚中的反应得到 Coruscanone A,为 (Z)- 和 (E)-甲基烯醇化物 (43%) 的~3:2 混合物;其他产物 (10%) 来自三酮五元环的膨胀和芳构化。Coruscanone