*3.4. Catalytic Oxidation Reactions*

Catalytic experiments were performed in an autoclave (Microclave 50 mL reactor, Autoclave Engineers) charged with an appropriate amount of guaiacyl glycerol-β-guaiacyl ether (GGGE), catalyst (40 mg) and acetonitrile (10 mL) as the solvent. The reactor was pressurized with 5 bar of 20% oxygen in argon, and heated to the desired reaction temperature. Mechanical stirring of the reactor (300 rpm) was started once a temperature of 20 ◦C below the set point was reached. After the reaction, the autoclave was quenched in cold water, the catalyst removed by filtration and the reaction mixture subjected to analysis.

In the catalyst recyclability study, the catalyst was recovered by filtration after each reaction run, thoroughly washed with acetonitrile, dried overnight at 60 ◦C and calcined at 450 ◦C for 6 h before being used in the next reaction run as described above.
