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 withmetallicions: 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 chemicalindustry,is a reaction frequently used in organic synthesis, asan efficient and economical wayto protect the carbonyl groupsin a synthetic process.The acetaldehyde showedthe higher reactivity in the reaction of hemiacetal synthesis,the aromatic ring decreased the reaction rate and the Zn2+turned out to bethe most reactivemetallic ion, withthelowerenergy values.