Improved methodologies for synthesis of prenylated xanthones by microwave irradiation and combination of heterogeneous catalysis (K10 clay) with microwave irradiation
作者:Raquel A.P. Castanheiro、Madalena M.M. Pinto、Sara M.M. Cravo、Diana C.G.A. Pinto、Artur M.S. Silva、Anake Kijjoa
DOI:10.1016/j.tet.2009.03.019
日期:2009.5
been synthesized for the first time by the microwave irradiation method. Prenylation of the xanthone building blocks 1 and 2 with prenyl bromide in alkaline medium, using microwave irradiation, gave the oxyprenylated xanthones 4 and 6, as major products in high yields, as well as diprenylated by-products (5, 7, 8, and 9) in very low yields. Microwave irradiation of oxyprenylated xanthones 4 and 6 furnished
十一异戊烯化呫吨酮衍生物(4 - 9,11 - 15)已合成的第一次通过微波照射方法。呫吨酮结构单元的异戊二烯化1和2与在碱性介质中的异戊烯基溴,使用微波辐射,得到oxyprenylated呫4和6,作为主要产物以高产率,以及作为副产物(diprenylated 5,7,8,和9)非常低的产量。微波辐射氧炔化的氧杂蒽4和6家具的三个新的重排克莱森产物(11,14,和15),以及先前描述的dihydrofuranoxanthones(12,13)。此外,三个新的(19,20,21)和三个以前的描述(16,17,18)dihydropyranoxanthones也已经从呫制备通过一锅法合成1,2,和3,使用蒙脱土K10粘土作为非均相催化剂,并在各种条件下将蒙脱石K10粘土与微波辐射结合使用。发现溶剂的存在和粘土的类型(商业或干燥的)对产品的收率有很大的影响。这是使用这些方法合成二氢吡喃并蒽酮衍