Abstract：

A domino reaction of readily available 1-carbamoyl-1-dimethylaminoalkenoylcyclopropanes in the presence of triflic anhydride (Tf2O) in N, N-dimethylformamide (DMF) is described, which provides a facile one-pot access to 2,3-dihydrofuro[3,2-c]pyridin-4(5H)-ones via tandem
formylation (Vilsmeier-type reaction), intramolecular cyclization, and ring-enlargement sequences.