Conversion of Monoterpenes into Flavors and Fragrances over Solid Acid Catalysts

Abstract

Monoterpenes are renewable resources that are widely used in the pharmaceutical, cosmetic and food industries as active components of drugs and ingredients of artificial flavours and fragrances. Acids catalyzed of terpenes are important synthetic routes to valuable compounds. Traditionally, strong homogeneous acid catalysts, e.g., sulphuric acid, have been used in acid reactions. However, solid acids have many advantages over liquid acids. They do less harm to the environment and do not have corrosion or effluent disposal problems. They are reusable and easy to be separated from liquid products. This review focuses on solid acid catalysts as potential heterogeneous catalysts for terpenes conversion into fragrances and flavours, replacing homogenous ones. Different reactions, such as hydration, alkoxylation, esterification, isomerization and cyclization of terpenes over heterogenous catalyts will be reviewed.