New DBU (1,8-diazabicyclo[5.4.0]undec-7-ene) assisted one-pot synthesis of 2,8-disubstituted 4H-1-benzopyran-4-ones
2-Hydroxy-3-(alkoxycarbonyl or prop-1-enyl)phenyl alkyl ketones are easily converted into 2,8-disubstituted (3-methyl)-4H-1-benzopyran-4-ones through a new DBU (1,8-diazabicyclo[5.4.0]undec-7-ene) assisted one-pot synthesis, by reaction with aroyl or alkanoyl chlorides or anhydrides. The method is simple, mild and convenient as compared to the existing multistep procedures.