3-(2-Furyl)propenoates IV-VIII were obtained by treatment of 5-phenoxy-2-furylmethylene derivatives I-III with alcoholic hydrogen chloride in one step. The probable transition mechanism of synthons I-III into the 2,4,5-trisubstituted furans is presented. The geometric isomers E-IV, Z-V and Z-VI, isolated in pure form, were transformed into the corresponding acids E-IX, Z-IX and E-X by base-catalyzed hydrolysis. Acid hydrolysis of the 1,3-diketone I afforded (4Z,6Z)-6-acetyl-7-hydroxy-2,4,6-octatrien-4-olide (XI). Structure of the products was verified by spectral (IR, UV, NMR and mass) methods.
通过用酒精性氢氯酸一步处理5-苯氧基-2-呋喃甲醛衍生物I-III,得到了3-(2-呋喃基)丙烯酸酯IV-VIII。文中还介绍了可能的合成路线,将合成原料I-III转化为2,4,5-三取代呋喃。分离出的几何异构体E-IV、Z-V和Z-VI被碱催化水解转化为相应的酸E-IX、Z-IX和E-X。将1,3-二酮I酸水解后得到(4Z,6Z)-6-乙酰基-7-羟基-2,4,6-辛三烯-4-酮(XI)。通过光谱(红外、紫外、核磁共振和质谱)方法验证了产物的结构。