Oxidation of Alcohols by Ca(OCl)2-Al2O3, Bull. Korean Chem. Soc., 1988, Vol. 9, No. 1, pp 60
Typical procedure
In a typical oxidation, to a stirred solution of an alcohol (0.6 mmol) in benzene (10mL) was added a grounded solid mixture of calcium hypochlorite (0.68g, 2.4 mmol) and basic alumina (0.68g) at room temperature. The mixture was stirred further at room temperature. The reaction mixture was filtered and the solvent was evaporated to afford the crude product. The yield was determined by GLC.
Benzyl alcohol -> Benzaldehyde, 99%, reaction time: 4h;
o-Chlorobenzyl alcohol -> o-Chlorobenzaldehyde, 95%, reaction time:7 h:
p-Chlorobenzyl alcohol -> p-Chlorobenzaldehyde, 96%, reaction time: 6 h;
Benzhydrol -> Benzophenone, 100%, reaction time: 3 h;
Cyclohexanol -> Cyclohexanone, 15%, reaction time: 8 h.
The given yields are yields determined by GLC. Isolated yields would be somewhat lower.
Oxidation of Alcohols with NiO2-Al2O3, Bull. Korean Chem. Soc., 1991, Vol. 12, No. 2, pp 115
The oxidation was performed by stirring the benzene solution (10mL) of an alcohol (1 mmol) with the solid mixture of nickel peroxide (0.46g, 1.50 mmol) and Al2O3 (W-200-B) (0.46g) at room temperature under nitrogen. After completiotion of the reaction, the solid was removed by the filtration and evaporation of the solvent afforded the product.
Benzyl alcohol -> Benzaldehyde, 98%, time: 3 h;
sec-phenethyl alcohol -> Acetophenone, 97%, time: 3 h;
p-Anisyl alcohol -> p-Anisaldehyde, (85%), time: 5 h;
Benzhydrol -> Benzophenone, (95%), time: 2 h;
Allyl alcohol -> Acrolein, 98%, time: 3 h;
3-Buten-2-ol -> 3-Buten-2-one, 98%, time: 2 h;
Crotyl alcohol -> Crotonaldehyde, 99%, time: 3 h;
Cinnamyl alcohol -> Cinnamaldehyde, 98%, time: 3 h;
Geraniol -> Geranial, 85%, time: 6 h.
Yields in parentheses are isolated yields. All other yields are yields determined by GC.
Environmentally-Friendly TEMPO-Mediated Oxidation of Alcohols with Poly[4-(diacetoxyiodo)styrene], Synthesis, 2003, No. 1, pp 21-23
Abstract: Primary and secondary alcohols were successfully oxidized to the corresponding aldehydes and ketones in good yields, respectively, with poly[4-(diacetoxyiodo)styrene] (PSDIB) in the presence of TEMPO (cat.) in acetone, as environment-friendly method.
Poly[4-(diacetoxyiodo)styrene]
A mixture of polystyrene (Aldrich Co. No. 33165-1, average M.W. ca. 200 000 and 4 000, 16g, 153 mmol), I2 (18g, 71 mmol), I2O5 (7g, 21 mmol), CCl4 (40mL), and 50% H2SO4 (35mL) in nitrobenzene (200mL) was kept at 90° C for 72 h. The reaction mixture was then diluted with CHCl3 (100mL) and precipitated by the addition of MeOH (1500mL). The precipitates were collected by filtration to give poly(4-iodostyrene). 30% H2O2 (40mL) was added dropwise to Ac2O (145mL) at 0° C. The solution was slowly warmed to room temperature and stirred overnight. To this solution was added poly(4-iodostyrene) (8g) and the solution was kept at 50° C overnight. Et2O was then added to the solution for precipitation and the product (ca. 9g) was collected by filtration.
Oxidation of Alcohols with Poly[4-(diacetoxyiodo)styrene] (PSDIB); General Procedure
PSDIB (0.6g, 1.2 mmol) was added to a solution of the appropriate alcohol (1 mmol) and TEMPO (0.031g, 0.2 mmol) in acetone (2mL) and the mixture was stirred at room temperature for the time given below. At end of reaction, Et2O (10mL) was added and the reaction mixture was filtered to remove the polymer. After removal of the solvent from the filtrate, the corresponding carbonyl compound was obtained in over 95% purity. If necessary, the filtrate was poured into H2O and extracted with Et2O (3 × 10mL). The combined organic extracts were dried over Na2SO4, filtered and the solvent was removed in vacuo. The residue was chromatographed on silica gel to give the pure carbonyl compound. The polymer reagent can be regenerated by treating poly(4-iodostyrene) with peracetic acid to give PSDIB and reused for the same reaction.
Benzyl alcohol -> Benzaldehyde, 90%, time: 2 h;
p-Methylbenzyl alcohol -> p-Methylbenzaldehyde, 93%, time: 2 h;
1-Phenyl-1-propanol -> 1-Phenyl-1-propanone, 94%, time: 6 h.
Oxidation of Alcohols to Carbonyl Compounds using Chromic Anhydride-Chlorotrimethylsilane-Alumina, Bull. Korean Chem. Soc., 1989, Vol. 10, No. 5, pp 471
Typical procedure
Chromic anhydride (10g, 100 mmol) and chlorotrimethylsilane (21g, 200 mmol) were added to carbon tetrachloride (150mL). The mixture was stirred for 30 minutes or until a dark red solution was obtained. Basic alumina (50g, 500 mmol) was added. To the stirred heterogenous solution was slowly added 1-hexanol (7.6g, 75 mmol) as a solution in a small amount of carbon tetrachloride. After 2 hours of vigorous stirring, the whole reaction mixture was filtered through a short column of silica gel. The clear filtrate was concentrated on a rotary evaporator. Distillation of the crude product using a short-path distilling apparatus or Kugelrohr afforded 6.8g (83%) of pure hexanal (bp 129-131° C)
This oxidation can be carried out on a 1-30g scale without any problems or major modification of the procedure.
Benzyl alcohol -> Benzaldehyde, 90%, time: 30 min;
p-Methoxybenzyl alcohol -> p-Methoxybenzaldehyde, 94%, time: 1 h;
p-Nitrobenzyl alcohol -> p-Nitrobenzaldehyde, 88%, time: 1 h;
