3,4-dihydroxyhexane-2,5-dione

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: A solution of methyl glyoxal 43% wt in water (2.00 g, 11.9 mmol), hydroxy-acetone (4.42 g, 59.7 mmol), and acetic acid (1.43 g, 23.8 mmol) in water (0.9 ml) were stirred during 16 hours at 70° C. (pH of the reaction medium was around 2.0). At the end of the reaction the reaction mixture was concentrated under reduced pressure giving 2.1 g of the crude 3,4-dihydroxyhexane-2,5-dione (56% purity measured by GC vs. internal standard). Crude 3,4-dihydroxyhexane-2,5-dione was distilled under reduced pressure to give 3,4-dihydroxyhexane-2,5-dione (1.56 g, 74% purity, 66% yield) as a pale yellow solid. The product obtained had the same 1H-NMR spectra as those described in Büchi et al, J. Org. Chem., 1973, 38, 123. At the end of the reaction the reaction mixture was concentrated under reduced pressure

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: A solution of methyl glyoxal 43% wt in water (2.00 g, 11.9 mmol), hydroxy-acetone (4.42 g, 59.7 mmol), and acetic acid (1.43 g, 23.8 mmol) in water (0.9 ml) were stirred during 16 hours at 70° C. (pH of the reaction medium was around 2.0). At the end of the reaction the reaction mixture was concentrated under reduced pressure giving 2.1 g of the crude 3,4-dihydroxyhexane-2,5-dione (56% purity measured by GC vs. internal standard). Crude 3,4-dihydroxyhexane-2,5-dione was distilled under reduced pressure to give 3,4-dihydroxyhexane-2,5-dione (1.56 g, 74% purity, 66% yield) as a pale yellow solid. The product obtained had the same 1H-NMR spectra as those described in Büchi et al, J. Org. Chem., 1973, 38, 123. At the end of the reaction the reaction mixture was concentrated under reduced pressure

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: A solution of methyl glyoxal 40% wt in water (9 g, 50 mmoles), zinc acetate (0.44 g) and hydroxy-acetone (7.4 g) in ethyl acetate (20 ml) were stirred during 40 h at 38/40° (pH of the reaction medium was around 4.5). At the end of the reaction (which can be checked by gas chromatography), the reaction mixture was extracted with ethyl acetate (3×50 ml). The organic phase was washed to neutral with brine (1×), dried over magnesium sulphate and concentrated under vacuum giving 6 g of the crude 3,4-dihydroxyhexane-2,5-dione who was Bulb-to-bulb distilled at 0.1 mbar and 120-150° to obtain 3.8 g of a mixture of the two 3,4-dihydroxyhexane-2,5-dione isomers. At the end of the reaction (which can be checked by gas chromatography) the reaction mixture was extracted with ethyl acetate (3×50 ml) The organic phase was washed to neutral with brine (1×) dried over magnesium sulphate concentrated under vacuum

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: A solution of methyl glyoxal 40% wt in water (9 g, 50 mmoles), zinc acetate (0.44 g) and hydroxy-acetone (7.4 g) in ethyl acetate (20 ml) were stirred during 40 h at 38/40° (pH of the reaction medium was around 4.5). At the end of the reaction (which can be checked by gas chromatography), the reaction mixture was extracted with ethyl acetate (3×50 ml). The organic phase was washed to neutral with brine (1×), dried over magnesium sulphate and concentrated under vacuum giving 6 g of the crude 3,4-dihydroxyhexane-2,5-dione who was Bulb-to-bulb distilled at 0.1 mbar and 120-150° to obtain 3.8 g of a mixture of the two 3,4-dihydroxyhexane-2,5-dione isomers. At the end of the reaction (which can be checked by gas chromatography) the reaction mixture was extracted with ethyl acetate (3×50 ml) The organic phase was washed to neutral with brine (1×) dried over magnesium sulphate concentrated under vacuum

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: A solution of methyl glyoxal 43% wt in water (2.00 g, 11.9 mmol), hydroxy-acetone (4.42 g, 59.7 mmol), and acetic acid (1.43 g, 23.8 mmol) in water (0.9 ml) were stirred during 16 hours at 70° C. (pH of the reaction medium was around 2.0). At the end of the reaction the reaction mixture was concentrated under reduced pressure giving 2.1 g of the crude 3,4-dihydroxyhexane-2,5-dione (56% purity measured by GC vs. internal standard). Crude 3,4-dihydroxyhexane-2,5-dione was distilled under reduced pressure to give 3,4-dihydroxyhexane-2,5-dione (1.56 g, 74% purity, 66% yield) as a pale yellow solid. The product obtained had the same 1H-NMR spectra as those described in Büchi et al, J. Org. Chem., 1973, 38, 123. At the end of the reaction the reaction mixture was concentrated under reduced pressure