The crucial factor of the reaction of 2,6-di-tert-butylphenol with alkali hydroxides is temperature, depending on which two types of potassium or sodium 2,6-di-tert-butylphenoxides are formed. These types exhibit different catalytic activity in the alkylation of 2,6-di-tert-butylphenol with methyl acrylate. More active forms of 2,6-But 2C6H3OK or 2,6-But 2C6H3ONa are synthesized at temperatures higher than 160 °C and are predominantly the monomers, which dimerize on cooling. The data of 1H NMR, electronic, and IR spectra for the corresponding forms of 2,6-But 2C6H3OK and 2,6-But 2C6H3ONa isolated in the individual state are in agreement with cyclohexadienone structure. In DMSO or DMF, the dimeric forms of 2,6-di-tert-butylphenoxides react with methyl acrylate to form methyl 3-(4-hydroxy-3,5-di-tert-butylphenyl)propionate in 64–92% yield.