writer：Peng Huang, Ning Zhang,* Rui Zhang, and Dewen Dong*
keywords：Vilsmeier reaction, pyridin-4(5H)-ones, ring-enlargement
source：期刊
specific source：Organic Letters
Issue time：2012年

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.