Thermochemical study of aliphatic and phenyl-substituted geminal diacetates

The standard enthalpies of combustion _cH^o of aliphatic diacetates1 and aromatic diacetates2 were measured calorimetrically. The enthalpies of vaporization _vapH^o or sublimation _subH^o of1 and2 were obtained from the temperature function of the vapor pressure measured in a flow system. From _fH^o(g) of1 and2 new values of group increments for the estimation of standard enthalpies of formation of these classes of compounds were derived. The geminal interaction energy between the geminal acyloxy groups shows no anomeric stabilization.Geminal Substituent Effects, Part 12, for part 11 see Ref. 7.