4-Ethoxycarbonyl-3,5-dimethyl-2-cyclohexen-1-one was obtained in 95 % yield via Robinson annulation of ethyl acetoacetate with acetaldehyde over sodium carbonate. The Robinson annulation catalyzed by sodium carbonate system was extended to diverse substrates. Under the catalysis of this system, both aliphatic aldehydes and aromatic aldehydes can be smoothly converted into corresponding disubstituted cyclohexenones. The cyclization product, 4-ethoxycarbonyl-3,5-dimethyl-2-cyclohexen-1-one can be almost quantitatively converted into the key intermediate 3,5-dimethyl-2-cyclohexenone through saponification and decarboxylation, and the yield of 3,5-dimethyl-2-cyclohexenone was 99 %. Direct dehydrogenation aromatization of 3,5-dimethyl-2-cyclohexenone was successfully realized to yield 3,5-dimethylphenol. The structures of the product and intermediates were characterized by 1HNMR and 13CNMR. The total yield of 3, 5-dimethylphenol was 66 % under the strategy established in this paper. Besides, this method was successfully applied to the synthesis of 3-methyl-5-propylphenol, which exhibited universal applicability.