Alcohol dehydration. Isotope studies of the conversion of 3-pentanol

Three deuterated 3-pentanols and undeuterated 3-pentanol were converted usi ng an alumina catalyst. Similar values of the kinetic isotope effect (KIE; k(H)/k(D)) were obtained for the rate of conversion of 3-pentanol and the r ate of H(D) removal in forming the alkene products. The data support a cata lytic dehydration mechanism that involves a concerted removal of H(D) from the -CH2-xDx group and OH (or O) from the carbinol carbon and with a timing such that the transition state resembles neither a carbonion-like nor carb enium-like species. (C) 1999 Elsevier Science B.V. All rights reserved.