Vibrational Circular Dichroism study of chiral food additives: γ-valero- and γ-caprolactone
M.Sánchez Valera, R.Casas Jaraíces, M.Montejo, P.G.Rodríguez Ortega
Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy Volume 247, 15 February 2021, 119140
γ-valerolactone and γ-caprolactone are commonly used as flavor additives in the food industry. In the present work we fully explore the molecular structure and conformational distribution of enantiopure γ-valerolactone and γ-caprolactone in solution state by using Vibrational Circular Dichroism (VCD) spectroscopy assisted by quantum chemical calculations. In order to establish the most accurate DFT method for this type of samples a set of methods and basis sets have been implemented and their performances have been compared. Subsequently, we have performed a complete vibrational assignment, which allowed to detect certain key vibrational features related to specific solution-state conformational speciation. In spite of the rigidity of the samples being studied, our results point to the incidence of conformational mixture in CCl4 solution in both samples.
VCD, FTIR, Lactones, DFT