Chemistry of ketene acetals II. A simple route to 2,2-dialkoxytetrahydrofurans, γ-butyrolactones, 2-(5H)-furanones and 2-alkoxy-4,5-dihydrofurans

2,2-Dialkoxytetrahydrofurans $\text{3}$ (a,b) have been synthesized from epoxides $\text{1}$ and ketene acetals $\text{2}$ using ZnCl₂ as a catalyst. By simple reactions compounds $\text{3}$ were converted into γ-butyrolactones $\text{5}$, 2-(5H)-furanones $\text{7}$ and 2-alkoxy-4,5-dihydrofurans $\text{8}$.