Synthesis of Chroman-4-ones with gem-Difluoroalkyl Side Chains in Position 2

New chroman-4-ones with gem -difluoroalkyl side chains in position 2 are easily accessible in five steps from salicylaldehyde-type derivatives. The crucial intermediates are propargylic alcohols bearing a CF 2 R substituent on the triple bond and the key step is their based-mediated isomerization into the corresponding enones. After MOM deprotection, an intramolecular oxa-Michael addition affords the target molecules in good overall yields. Such chromanones appear as useful intermediates for the preparation of bioactive oxygen-containing heterocycles with gem -difluoroalkyl side chains.