Addition des thiols sur les cetones—II : Mecanisme de l'addition du propanethiol

Addition of propanethiol to cyclohexanone in aqueous ethanol involves two consecutive steps, both of them rate limiting. The first step is the addition of the thiol to the conjugate acid of the ketone, giving an instable intermediate hemithioketal. Another thiol molecule adds to this, giving the thioketal. From the rate expression the thiol addition rate constant to the cyclohexanone was calculated.