Equilibria in cyanohydrin formation from, and the kinetics of reduction by sodium borohydride of, substituted acetylbiphenyls

Abstract

Equilibria in cyanohydrin formation from 4′-substituted-4-acetylbiphenyls in 80% v/v dioxan–water at 30 °C and their rates of reduction by sodium borohydride in propan-2-ol at 30,35, and 40 °C have been studied. The Hammett equation is obeyed by both these reactions. The ρ values are found to be 0.52 and 0.66 at 30 °C for cyanohydrin formation and for borohydride reduction, respectively. These results agree with the earlier conclusion that the transmission of electronic effects of substituents is less in the biphenyl than in the benzene system.