One-step microwave-assisted asymmetric cyclisation/hydrogenation of citronellal to menthols using supported nanoparticles on mesoporous materials.
The selective conversion of citronellal to menthols, with good diastereoselectivities to (-)-menthol for the case of (+)-citronellal as starting material, can effectively be carried out in a one-step reaction under microwave irradiation catalysed by supported nanoparticles on mesoporous materials. 2% Pt/Ga-MCM-41 was found to be the optimum catalyst for the reaction, with a quantitative conversion of starting material and selectivities above 85% to menthols obtained in short reaction times (typically 15 min). These results constitute the first report of a simple microwave-assisted one-step cyclisation/hydrogenation process for the production of menthols.
Balu
Alina Mariana
AM
Departamento de Química Orgánica, Universidad de Córdoba, Edificio Marie Curie, Ctra Nnal IV, Km 396, E-14014, Córdoba, Spain.
Campelo
Juan Manuel
JM
Luque
Rafael
R
Romero
Antonio Angel
AA
D000080462:Acyclic Monoterpenes; D000447:Aldehydes / Q000737:chemistry*; D003500:Cyclization; D006865:Hydrogenation; D008610:Menthol / Q000737:chemistry*; D008872:Microwaves; D039821:Monoterpenes / Q000737:chemistry*; D053758:Nanoparticles / Q000737:chemistry*; D013237:Stereoisomerism
D000080462:Acyclic Monoterpenes; D000447:Aldehydes; D039821:Monoterpenes; D008610:Menthol; C108217:citronellal