LAUSR

An efficient and Brønsted acid-free route to synthesize monoterpene ethers was developed using SnBr2 as inexpensive and commercially affordable catalyst. This process consists of the synthesis of α-terpinyl alkyl ethers in SnBr2-catalyzed reactions of β-pinene with alkyl alcohols. The catalytic activity of various tin(II) salts was assessed and compared to that of other homogeneous Lewis and Brønsted acids, in etherification reactions of β-pinene with methyl alcohol. SnBr2 was the most active and selective catalyst toward α-terpinyl methyl ether. Tin(II) bromide is a water tolerant Lewis acid, which emerges as an efficient, simple, and cheap catalyst. The influence of the main reaction parameters was investigated, including SnBr2 concentration, temperature and reaction time. Different alcohols and monoterpenes were also studied. The impact of the substrate nature on the reaction selectivity was assessed.