Gold-catalyzed formal [4+2] benzannulation between enynal or enynone units, including ortho-alkynyl (oxo) benzenes, and 2 pi-systems, such as alkynes and carbonyl compounds (enol forms), produces aromatic ketones in good to high yields. By simply changing the catalyst from gold to copper-Bronsted acid system, decarbonylated aromatic compounds can be prepared in the reactions using alkynes as the 2 pi-system. An efficient synthetic approach to angucyclinone antibiotics, (+)-ochromycinone and (+)-rubiginone B-2, is developed by applying the present benzannulation to an intramolecular version. The reaction proceeds most probably through the formation of the benzo[c]pyrylium ate complex via the intramolecular nucleophilic addition of the carbonyl oxygen atom to the alkyne part of enynal or enynone units, which is induced by carbophilic gold catalyst.