Phosgene reacts with 2, 6-dimethyl-4H-pyran-4-one at room temperature to yield 2, 6-bis (4′-chloro-2′, 6′-dimethylphenyl)-4H-pyran-4-one (I), and 2-(4′-chloro-2′, 6′- dimethylphenyl)-6-methyl-4H-pyran-4-one (II). The structure assignment and the mechanism of formation is discussed. Some 4H-ylidene derivatives of I and II were prepared.
