Theoretical study of hemiacetal synthesis catalyzed by Lewis acids

A theoretical study of the synthesis of methylhemiacetal acetaldehyde, methylhemiacetal benzaldehyde, 4-methyl benzaldehyde methylhemiacetal and 4-nitro methylhemiacetal benzaldehyde was carried out, comparing the aldehydes reactivity fromthe reaction with methanol, catalyzed with metallicions: Zn2+; Co2+, Mn2+; Cu2+and Ni2+, through the analysis of the corresponding reaction intermediates and indicating the influence of the aromatic ring and metal ions on the reaction rate.The activation energies and the reaction intermediatesenergies were calculated throughthe Universal Force Field (UFF) method. The calculated values agreedwith the literature.The hemiacetal synthesis, in addition to its usefulness within the chemical industry,is a reaction frequently used in organic synthesis, as an efficient and economical way to protect the carbonyl groups in a synthetic process.The acetal dehyde showed the higher reactivity in the reaction of hemiacetal synthesis,the aromatic ring decreased the reaction rate and the Zn2+turned out to bethe most reactive metallicion, with the lower energy values.