A flavoring material in roasted coffee, 2-hydroxy-3-methyl-2-cyclohexen-1-one (1 a) and its homologs (1 b, 1 c, and 1 d) were synthesized through the acyloin condensation for corresponding diethyl 2-alkyladipates. The flavor property of the 3-methyl diketone (1 a) was burnt sugar-like, while that of the ethyl homolog (1 b) was strong burnt sugar-like with sweet overtones. The isopropyl derivative (1 c) possessed a fresh grass odor and the benzyl derivative (1 d) a wood-like odor with phenolic overtones.