Premium
Sustainable Isomerization of α‐Pinene Oxide to trans ‐Carveol using Formic Acid/Aniline System at Room Temperature
Author(s) -
Ravi Krishnan,
Naikwadi Dhanaji R.,
Bankar Balasaheb D.,
Biradar Ankush V.
Publication year - 2021
Publication title -
advanced sustainable systems
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.499
H-Index - 24
ISSN - 2366-7486
DOI - 10.1002/adsu.202000212
Subject(s) - isomerization , chemistry , formic acid , selectivity , solvent , catalysis , oxide , organic chemistry , brønsted–lowry acid–base theory
trans ‐Carveol is an essential and expensive chemical used as valencia orange essence oil in the fragrance industry, and can be obtained through Brønsted acid‐catalyzed isomerization of α‐pinene oxide (APO) using hazardous solvent at higher temperatures. Therefore the development of a simple, metal‐free, and cost‐effective, sustainable method for isomerization of APO at milder conditions is desired. In this study, in situ formed formanilide (IFF) and tetrahydrofuran are used as active solvents and formic acid used as a Brønsted acid catalyst for selective isomerization of APO. Under the optimized conditions, the maximum 80% selectivity of trans ‐carveol is achieved with complete APO conversion in 30 min at room temperature. The solvent system's practical utility is demonstrated at a 10 g scale with complete conversion and 76% selectivity at room temperature within 60 min. Furthermore, isotopic labeling experiments show donation of a proton from the IFF solvent.