6-(ω-Hydroxyalkyl)-2, 3-dimethoxy-5-methyl-1, 4-benzoquinones (3) and 6-(ω-acetoxyalkyl)-2, 3-dimethoxy-5-methyl-1, 4-benzoquinones (26) having various carbon numbers (n) of the side chain were synthesized by the Friedel-Crafts coupling of 3, 4, 5-trimethoxytoluene (4) and ω-acetoxyalkanoyl chlorides (5) as a key step. The Fremy's salt oxidation or the salcomine-catalyzed oxidation of 6-(ω-hydroxyalkyl)-2, 3-dimethoxy-5-methylphenols (25) and their acetates (24), the key intermediates of the process, gave rise to 3 and 26, respectively, in good yields. The described method provides a good yield of the 1, 4-benzoquinones and is suitable for the synthesis of other quinonyl analogs. The effect on lipid peroxidation in canine brain homogenate of the 1, 4-benzoquinones (3) having various carbon numbers (n) of the side chain was studied. Among the compounds tested, 3 having a carbon number in the range of n=9-13 showed rather strong antioxidant activity.