Synthesis and reactions of reduced flavones

Abstract

The cycloadditions of a series of 4H-pyran-4-ones 3c–e with electron-rich dienes 11a,b to give reduced flavones 12 is described. The subsequent reactions of these reduced flavones with HCl, trifluoroacetic anhydride, ethyl anthranilate 19a and anthranilonitrile 19b is also described.