4-Ethylphenol methylenehydroxylase from Pseudomonas putida JD1 acts by dehydrogenation of its substrate to give a quinone methide, which is then hydrated to an alcohol. It was shown to be active with a range of 4-alkylphenols as substrates. 4-n-Propylphenol, 4-n-butylphenol, chavicol, and 4-hydroxydiphenylmethane were hydroxylated on the methylene group next to the benzene ring and produced the corresponding chiral alcohol as the major product. The alcohols 1-(4'-hydroxyphenyl)propanol and 1-(4'-hydroxyphenyl)-2-propen-1-ol, produced by the biotransformation of 4-n-propylphenol and chavicol, respectively, were shown to be R(+) enantiomers. 5-Indanol, 6-hydroxytetralin, 4-isopropylphenol, and cyclohexylphenol, with cyclic or branched alkyl groups, gave the corresponding vinyl compounds as their major products.