One-pot synthesis of coumarin substituted dihydrofurans

摘要

A sequential one-pot two-step tandem reaction for an efficient synthesis of 2,3-dihydrofurans substituted with 2H-benzopyrans has been developed. One-pot reaction of in situ formed benzopyran substituted pyridinium ylides with aromatic aldehydes and dimedone gives corresponding 2,3-dihydrofurans in good yields. The structures of the final compounds have been assigned as trans-2,3-dihydrofurans on the basis of their NMR spectra.