Preparation of Carboxylic Esters and Phosphoric Esters by the Activation of Alcohols

Abstract The reaction of dibenzyl hydrogen phosphate with alcohols in the presence of diethyl azodicarboxylate and triphenylphosphine, followed by catalytic hydrogenation, resulted in the formation of the corresponding alkyl dihydrogen phosphates. When p-tolyl dihydrogen phosphate and ethanol were allowed to react with diethyl azodicarboxylate and triphenylphosphine, ethyl p-tolyl hydrogen phosphate and diethyl p-tolyl phosphate were obtained. On the other hand, dipyridinium p-tolyl phosphate gave ethyl p-tolyl hydrogen phosphate and di p-tolyl pyrophosphate. The reaction of alkyl N,N′-tetraethylphosphorodiamidites with carboxylic acids in the presence of diethyl azodicarboxylate resulted in the formation of corresponding carboxylic esters. When these reactions (benzoylation) were carried out with the use of optically active 2-octanol, 2-octyl benzoate was obtained with inverted configuration.