DBU-mediated regioselective intramolecular cyclization/dehydration of ortho diketo phenoxyethers: a synthesis of 2,3-substituted γ-benzopyranones

The regioselective cyclization/dehydration sequence of ortho diketo phenoxyethers induced by DBU has been explored. The results demonstrated a high degree of selectivity with preference for 6-exo-trig cyclization leading to the formation of γ-benzopyranone derivatives in good yield.