通过2-芳氧基乙醛缩醛的分子内环化,已经建立了一种有效的,对环境无害的非均相催化方法,用于合成2,3-未取代的苯并[ b ]呋喃。通过使用锡交换的H-β沸石(Sn-β)作为催化剂,可以以良好或极好的收率制备各种功能化的2,3-未取代的苯并[ b ]呋喃。Sn-β沸石催化剂还在间位取代的2-芳氧基乙醛缩醛的环化上表现出优异的形状选择性,并且优选形成高达97%的区域选择性的6-取代的异构体。而且,Sn-β沸石可以容易地回收和再利用而没有任何明显的活性损失。
4-Methacryloyloxymethyl-1,3-dioxolanes substituted at the 2 position with perfume and herbicide aldehyde residues were synthesized either by acetalization or by transacetalization involving 2,3-dihydroxypropyl methacrylate. The effect of the 2-substituent of the dioxolane ring on the rate of hydrolysis was remarkable.