Conformation and reactivity. Part VIII. Kinetics of the esterification with diazodiphenylmethane in toluene of the trans-decalincarboxylic acids, of the 4-t-butylcyclohexanecarboxylic acids, of certain trans-4-substituted cyclohexanecarboxylic acids, and of cyclohexanecarboxylic acid

Abstract

The reaction between a carboxylic acid and diazodiphenylmethane in toluene is considered in terms of the supposition that the monomer is more reactive than the dimer, and that the system shows general acid-catalysis of the type observed for some related systems.

The rates of esterification with diazodiphenylmethane in toluene at 30° of the acids mentioned in the title have been measured. For the trans-4-X-cyclohexanecarboxylic acids, X = CO₂Et, CO₂Me, Br, or CN. Two ‘1,3-axial hydrogen atom’ interactions have little effect on the reactivity of the carboxy-group, but three of these interactions, as in the decalin 1-axial acid cause marked retardation of the reaction. The rate coefficent for the reaction of the 1-equatorial acid is about 25% greater than that for the 2-equatorial acid. The polar substituents, X, exert a greater effect upon reactivity for reactions in toluene than for those in alcohols.