Ring-Opening Fluorination of Cyclopropylmethanols and Cycloprpanecarbardehydes with Diethylaminosulfur Trifluoride

Abstract The reaction of cyclopropylmethanols bearing aromatic substituents on their cyclopropane rings with diethylaminosulfur trifluoride (DAST) effectively caused ring-opening fluorination to produce homoallylic fluorides. This reaction proceeded via a carbocation intermediate. DAST reacted with cyclopropanecarbaldehydes having electron donating aromatic substituents to cause ring-opening fluorinations with the addition of two fluorine atoms to afford 1,4-difluorobut-1-enes.