Abstract 4-Hydroxyequilin, 4-hydroxyequilenin, and 16α-hydroxyequilenin were synthesized as authentic specimens for the metabolic studies of equine estrogens. The synthetic route leading to the 4-hydroxylated compounds was started from o-vanillin, which was transformed into the β-ketosulfoxide (2b) by sequential multistep reactions. This was converted to the α, β-unsaturated ketone (3) as Michael acceptor. Condensation of 3 with ...
