Shifting the Reactivity of Bis-propargyl Ethers from Garratt–Braverman Cyclization Mode to 1,5-H Shift Pathway To Yield 3,4-Disubstituted Furans: A Combined Experimental and Computational Study
作者:Joyee Das、Eshani Das、Saibal Jana、Partha Sarathi Addy、Anakuthil Anoop、Amit Basak
DOI:10.1021/acs.joc.5b02246
日期:2016.1.15
departure from this usual route, several aryl/vinyl bis-propargyl ethers with one of the acetylenic arms ending up with 2-tetrahydropyranyloxy methyl or ethoxy methyl have been shown to follow the alternative intramolecular 1,5-H shift pathway upon base treatment. The reaction has led to the formation of synthetically as well as biologically important 3,4-disubstituted furan derivatives in good yields. The
碱处理后的芳基或乙烯基取代的双炔丙基醚通常通过Garratt-Braverman(GB)环化途径形成邻苯二甲酸酯。与通常的路线大相径庭的是,一些炔基/乙烯基双炔丙基醚的炔属臂之一最终以2-四氢吡喃基氧基甲基或乙氧基甲基结尾,遵循了基于分子的另一种分子内1,5-H转移途径治疗。该反应导致以高收率形成合成的以及生物学上重要的3,4-二取代的呋喃衍生物。溶液中最初形成的E异构体(CDCl 3)缓慢异构化为Z异构体,表明后者的稳定性更高。还评估了影响1,5-H移位和GB重排之间相互作用的因素,并且该结果得到基于DFT的计算研究的支持。