Investigation of Prins reaction for the synthesis of 2, 4- disubstituted tetrahydropyran derivatives and 1, 3-dioxanes using polyaniline supported acid as reusable catalyst

Abstract

The Prins cyclization of homoallyl alcohol with a variety of aldehydes were observed under reflux condition in dichloromethane using both polyaniline supported TsOH (PANI-TsOH) and FeCl3(PANI- FeCl3) as reusable acid catalysts with the formation of 2,4-disubstituted tetrahydropyran ether as single product. In case of 4-, 3- and 2- nitro benzaldehydes, the reaction generated acetal of the aldehyde and homoallylic alcohol as single product. Additionally, both catalysts were investigated for the synthesis of 1, 3-dioxane in dichloromethane under reflux and at ambient temperature. The Prins cyclization of 3-butene-1-ol with aromatic aldehydes yielded 2,4- disubstituted tetrahydropyran ether 4 as single product in dichloromethane using both PANI-TsOH and PANI-FeCL3 as reusable acid catalysts. Both catalysts were investigated for the synthesis of 1, 3-dioxane in dichloromethane.