Studies on Antioxidants. III. : Syntheses of ω, ω'-Bis(2(3 or 4)-hydroxyphenyl)alkanes and ω, ω'-Bis(2-hydroxy-3(4 or 5)-methylphenyl)alkanes and Their Antioxidant Activities

Abstract

In order to elucidate the correlation between chemical structure and antioxidant effect, syntheses were systematically carried out on the phenol derivatives of ω, ω'-bis(2-hydroxyphenyl)alkanes (Ia), ω, ω'-bis(3-hydroxyphenyl)alkanes (Ib), and ω, ω'-bis(4-hydroxyphenyl)-alkanes (Ic), and cresol derivatives of ω, ω'-bis(2-hydroxy-3-methylphenyl)alkanes (IIa), ω, ω'-bis(2-hydroxy-4-methylphenyl)alkanes (IIb), and ω, ω'-bis(2-hydroxy-5-methylphenyl)alkanes (IIc), with 5, 7, and 10 carbons in the chain. Compounds of Ia, IIa, and IIb series were obtained by deriving the corresponding phenols to their esters, their Fries rearrangement to hydroxyketones, and their Clemmensen reduction to the objective compounds. Compounds of Ib series were obtained from m-nitro derivatives by hydroxylation by the conventional method. Compounds of Ic and IIc series were obtained from the methyl ethers of the corresponding phenols by the method previously described. Antioxidant ability of these derivatives was examined and the compounds of II series with methyl group had better antioxidant activity than those of I series without the methyl group.