Exploitation of Liquid CO2 Based Greener Process for Valorization of Citronellal-Rich Essential Oils Into Flavor Grade (?)-Menthol Using Novel Sn/Al-B-NaYZE Composites

A two-step greener catalytic process has been developed for the semi-synthesis of (?)-menthol from citronellal-rich essential oils such as Cymbopogon winterianus and Corymbia citriodora by using novel bi-acidic composites. These composites (Al-B-NaYZE or Sn-B-NaYZE) were prepared impregnation Sn-B Al-B over NaYZE framework to increase Lewis Bronsted acidic sites. thoroughly characterized TDP, FT-IR, UV, XRD, SEM, HRTEM, SA, TGA. The composite Sn-B-NaYZE cyclized 99% citronellal isopulegol isomers with selectivity in 45 min under a liquid CO2 medium, while Al-B-NaYZE is showing 95% towards isomers. displayed enhanced due its higher characteristics. chiral study indicated that giving highest (94%) (?)-isopulegol. (+)-Citronellal citronella oil was found an ideal substrate production. It observed molar ratio base material NaY-Zeolite played major role activity Further, reduced 98% menthol 1%Pd/AC at 40 psi H2 pressure 1 h. reaction mixture slowly frozen -40 °C trouble-free isolation crude menthol. pharmaceutical flavor grade purified through esterification process. This be 100% biobased on 14C-radiocarbon-dating authenticate nature-identical.