# Sulfonic Resins as Catalysts for the Oxidation of Alcohols with H\({}_{2}\)O\({}_{2}\)/KBr
## 3 Materials and Methods  
Triflic acid (99%) was purchased from Fluorochem, _p_-toluenesulfionic acid was purchased from Alfa Aesar, and the resins (Aquivion PW97S, Aquivion P98, Nafion NR50, Amberlyst 15, Dowex 50W\(\times\)8 and Dowex 50W\(\times\)2) were purchased from Merck. Methyl1 oleate (96%, Alfa Aesar, Tewksbury, MA, USA), (\(-\))-menthol (99%, Sigma-Aldrich, St. Louis, MO, USA), 1-dodecanol (98%, Alfa Aesar) and 1-octadecanol (99%, Sigma-Aldrich) were used as received without further purification. 2-Methylcyclohexanol (97%, 1: \(trans/cis\) mixture) was a generous gift from FMC-Foret (currently Evonik Peroxide Spain, Zaragoza, Spain). The oxidized products were identified via NMR and/or GC-MS.  
Activation of Aquivion P98 [8]: a mixture of 5.0 g of Aquivion P98-SO\({}_{2}\)F (5.1 mmol of -SO\({}_{2}\)F groups), 30 mL of aqueous KOH (2.0 M) and 5 mL of DMSO was stirred at 120 \({}^{\circ}\)C for 72 h. The solid was filtered off and washed with distilled water until a neutral pH was obtained. The wet potassium form was treated with 30 mL of aqueous H\({}_{2}\)SO\({}_{4}\) (2.0 M) under stirring at 120 \({}^{\circ}\)C for 24 h. The solid was again filtered off and washed with distilled water until a neutral pH was obtained. The content of sulfonic acid sites was determined by indirect volumetric determination [32]. Then, 1.0 g of previously dried acidic Aquivion P98 was packed in a chromatographic column and a 2.0 M aqueous solution of NaCl was passed through the resin bed until a neutral pH was obtained. The resulting HCl solution was titrated with 1.0 mM of aqueous solution NaOH and phenolphthalein as an \begin{table}
\begin{tabular}{c c c c c c} \hline \hline
**Entry** & **Alcohol** & **KBr mol\%** & \
\begin{tabular}{c} **H\({}_{2}\)O\({}_{2}\)/Alcohol** \\ **Molar Ratio** \\ \end{tabular} & **t (h)** &
\begin{tabular}{c} **Reaction Mixture** \\ **Composition (\%) 2** \\ \end{tabular} \\ \hline
1 & 1-Dodecanol (**3a**) & 20 & 0.75 & 48 & **3a** (49) + **4a** (4) + **5a** (47) \\
2 & 1-Dodecanol (**3a**) & 20 & 2.0 & 96 & **3a** (18) + **4a** (8) + **5a** (74) \\
3 & 1-Dodecanol (**3a**) & 40 & 1.5 & 48 & **3a** (12) + **4a** (8) + **5a** (80) \\
4 & 1-Octadecanol (**3b**) & 40 & 1.5 & 48 & **3b** (34) + **4b** (13) + **5b** (53) \\
5 & 2-Methylcyclohexanol (**6**) 3  & 20 & 0.75 & 24 & 6 (3) + **7** (85) + **unk** (12) \\
6 & (\(-\))–Menthal (**8**) & 20 & 0.75 & 48 & **8** (36) + **9** (59) + **unk** (5) \\
7 & (\(-\))–Menthal (**8**) & 20 & 1.5 & 48 & **8** (17) + **9** (74) + **unk** (9) \\ \hline \hline \end{tabular}
\end{table} 
Table 4: Oxidation of different alcohols with KBr/H\({}_{2}\)O\({}_{2}\)/Dowex 50W\(\times\)8 1.  
indicator. The functionality of Aquivion P98-H\({}^{+}\) was 0.98 mmol H\({}^{+}\)/g (at least 96% of active sites exchanged). All the resins were titrated in the same way and the experimental functionalization results are shown in Table 5.  
All the resins were dried at 120 \({}^{\circ}\)C under vacuum overnight prior to use. Gas chromatography was performed using Agilent 7890A and 6890N chromatographs, both equipped with FID detectors, and ZB-5 HT Inferno capillary columns (30 m \(\times\) 0.25 mm \(\times\) 0.25 \(\upmu\)m). Helium was used as a carrier gas at 17 psi in the column head. Injector temperature: 280 \({}^{\circ}\)C. Detector temperature: 250 \({}^{\circ}\)C. Owen program: 70 \({}^{\circ}\)C (4 min, initial plateau), 25 \({}^{\circ}\)C min\({}^{-1}\) to 150 \({}^{\circ}\)C (ramp 1), 5 \({}^{\circ}\)C min\({}^{-1}\) to 250 \({}^{\circ}\)C (ramp 2), and 250 \({}^{\circ}\)C (15 min, final plateau). Retention times: _trans_-2-methylcyclohexanol (6 _trans_), 5.3 min; _cis_-2-methylcyclohexanol (6 _cis_), 5.4 min; 2-methylcyclohexanone (7), 5.5 min, (\(-\))-menthol (**8**), 7.1 min; (\(-\))-menthoe (**9**), 7.4 min; methyl 9(10)-oxostearate (**2a + 2b**), 24.9 min; and methyl 9(10)-hydroxysterate (**1a + 1b**), 25.2 min.