Synthesis of 4-trifluoromethanesulfonate substituted 3,6-dihydropyrans and their application in various C–C coupling reactions†
Abstract
The triflic acid mediated Prins cyclization of homopropargylic alcohols with aldehydes afforded 3,6-dihydro-2H-pyran-4-yl trifluoromethanesulfonates efficiently and highly regioselectively. The dihydropyran thus formed is transformed into different 4-alkyl and aryl substituted products using Suzuki, Heck, Stille and Sonogashira coupling reactions.