A novel synthesis of oxabicyclo[3.3.1]nonanone via (3,5)-oxonium-ene reaction.

Oxabicyclo[3.3.1]nonanone can conveniently be prepared by the reaction of trans-p-menth-6-ene-2,8-diol and aldehyde or epoxide mediated by boron trifluoride etherate in good yields. The reaction proceeds via (3,5)-oxonium-ene-type reaction.

Stereoselective one-pot, three-component synthesis of 4-aryltetrahydropyran via Prins-Friedel-Crafts reaction.

A diastereoselective one-pot, three-component Prins-Friedel-Crafts reaction was developed for the synthesis of 4-aryltetrahydropyran derivatives from the reaction of carbonyl compounds with homoallylic alcohol in the presence of arene promoted by boron trifluoride etherate.

Stereoselective one-pot, three-component synthesis of 4-amidotetrahydropyran.

The reaction of aldehyde with allylsilane in acetonitrile mediated by boron trifluoride etherate generated 4-aminotetrahydropyrans in good yields. The product is highly stereoselective.