| Abstract: | The rates of gas-phase elimination reactions of methyl benzoylformate ( 1 ) and 3-hydroxy-3-methyl-2-butanone ( 2 ) were obtained at T = 600 K. The two substrates undergo unimolecular first-order elimination for which the Arrhenius equations are, respectively, log k = 13.2 − 53270/(4.574 × 600) for ( 1 ) and log k = 12.4 − 53060/(4.574 × 600) for ( 2 ). The products of pyrolysis of ( 1 ) are benzaldehyde, formaldehyde and CO, while those of ( 2 ) are acetaldehyde and acetone. The kinetics of the elimination reactions show benzoylformic acid to be 106-fold more reactive than ( 1 ), and pyruvic acid ca. 105-fold more reactive relative to ( 2 ); an indication of the rate-controlling part played by the acidity of the hydrogen atom involved in the elimination process of the present compounds in this particular type of reaction. © 1997 John Wiley & Sons, Inc. Int J Chem Kinet 29: 295–298, 1997. |
