In contact with alumina, the title aldehyde 1 (R = H, Me, Cl) gives the chromones 5 and 9,12 whereas the acid 2 affords the chromones 7, 10 and acetophenone 23. Alumina converts the aldehyde 3 to the xanthone 14, and the corresponding acid 4 to the chromone 8 and diketone 24.