(3-methyl-4-oxobut-2-enyl) acetate

Conditions: temp:0.00; pressure:0.00; stir:

Conditions: temp:0.00; pressure:0.00; stir:

Conditions: temp:0.00; pressure:0.00; stir:

Conditions: temp:0.00; pressure:0.00; stir:

Conditions: temp:0.00; pressure:0.00; stir:

Conditions: temp:0.00; pressure:0.00; stir:

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

Procedure: To a solution of 4-acetoxy-2-methyl-2-buten-1-ol (6.69 g, 46.4 mmol) in dimethylformamide (40 ml) were added 2,2,6,6-tetramethyl-piperidine-1-oxy (0.39 g, 2.32 mmol, 5 mol %) and cuprous chloride (0.48 g, 4.64 mmol, 10 mol %). The mixture was subjected to reaction at 40° C. for 8 hours while bubbling oxygen at a rate of about 100 ml/min. After completion of the reaction, the reaction mixture was poured into ice-cooled water (30 ml) and extracted with ether (100 ml) three times. The extract was dried over anhydrous magnesium sulfate. Evaporation of the ether followed by purification by column chromatography (ethyl acetate-hexane (=1:3)) gave 4-acetoxy-2-methyl-2-buten-1-al (6.02 g, 42.3 mmol; Yield: 91.2%). The mixture was subjected to reaction at 40° C. for 8 hours while bubbling oxygen at a rate of about 100 ml/min After completion of the reaction the reaction mixture was poured into ice- extracted with ether (100 ml) three times The extract was dried over anhydrous magnesium sulfate Evaporation of the ether followed by purification by column chromatography (ethyl acetate-hexane (=1:3))

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

Procedure: 28.4 g (0.2 mole) of 2-methyl-4-acetoxy-2-butenal is dripped into a mixture of 23.3 g (0.22 mole) of o-formic acid methyl ester, 12.8 g (0.4 mole) of methanol and 0.35 g (2millimoles) of p-toluene-sulfonic acid. Acetalization takes place while the temperature rises. After 1 hour 2 g (15 millimoles) of quinoline is added and the whole is heated at 185° to 190° C (internal temperature) and at a pressure of 200 mm Hg for 20 minutes The methanol which is eliminated is distilled off in a 20-cm column. Then the pressure is adjusted to 20 mm Hg with the result that 23.2 g of 1-acetoxy-3-methyl-4-methoxy-1,3-butadiene in the form of a mixture of two geometric iosmers is obtained. The yield is 75% of the theory. the whole is heated at 185° to 190° C (internal temperature) at a pressure of 200 mm Hg for 20 minutes The methanol which is eliminated is distilled off in a 20-cm column

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

Procedure: To a solution of 4-acetoxy-2-methyl-2-buten-1-ol (6.69 g, 46.4 mmol) in dimethylformamide (40 ml) were added 2,2,6,6-tetramethyl-piperidine-1-oxy (0.39 g, 2.32 mmol, 5 mol %) and cuprous chloride (0.48 g, 4.64 mmol, 10 mol %). The mixture was subjected to reaction at 40° C. for 8 hours while bubbling oxygen at a rate of about 100 ml/min. After completion of the reaction, the reaction mixture was poured into ice-cooled water (30 ml) and extracted with ether (100 ml) three times. The extract was dried over anhydrous magnesium sulfate. Evaporation of the ether followed by purification by column chromatography (ethyl acetate-hexane (=1:3)) gave 4-acetoxy-2-methyl-2-buten-1-al (6.02 g, 42.3 mmol; Yield: 91.2%). The mixture was subjected to reaction at 40° C. for 8 hours while bubbling oxygen at a rate of about 100 ml/min After completion of the reaction the reaction mixture was poured into ice- extracted with ether (100 ml) three times The extract was dried over anhydrous magnesium sulfate Evaporation of the ether followed by purification by column chromatography (ethyl acetate-hexane (=1:3))

Conditions: temp:35.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: Crude 1-acetoxy-4-chloro-3-methyl-2-butene (194 g, Purity: 83.8%, 1 mol) was added to hexamine (168 g, 1.2 mol)/water (1 liter), and the mixture was stirred at 35° C. for 4 hours and then separated into aqueous and organic layers. 1,2-Dichloroethane (1 liter) was added to the aqueous layer, and the mixture was subjected to reaction at 72° C. for 6 hours while adjusting the pH with 1N sulfuric acid. The 1,2-dichloroethane layer was separated, 1,2-dichloroethane (1 liter) was added to the aqueous layer, and the reaction was carried out again. The 1,2-dichloroethane layers were combined and concentrated. The residue was distilled under reduced pressure to give 4-acetoxy-2-methyl-2-buten-1-al (98 g, 69%). bp.0.2-0.3 mmHg: 58°-66° C. separated into aqueous and organic layers 1,2-Dichloroethane (1 liter) was added to the aqueous layer the mixture was subjected to reaction at 72° C. for 6 hours The 1,2-dichloroethane layer was separated 1,2-dichloroethane (1 liter) was added to the aqueous layer concentrated The residue was distilled under reduced pressure

Conditions: temp:75.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: 1-Acetoxy-4-chloro-3-methyl-2-butene (7.8 g) was added to a suspension of hexamine (6.7 g) and acetonitrile (47 ml), and the mixture was stirred at room temperature for 16 hours. The precipitated crystals were separated by filtration to give crystals (12.5 g) of a quaternary ammonium salt. This salt (7.9 g) was dissolved in water (50 ml), and toluene (100 ml) was added. With stirring at 75° C., acetic acid (1.5 g per addition) was added 30 minutes, 1 hour and 2 hours after the beginning of the reaction. The reaction was stopped 6 hours after the beginning of the reaction. The toluene layer was separated and concentrated, and the resulting residue was purified by column chromatography on silica gel to give 4-acetoxy-2-methyl-2-buten-1-al (2.6 g, 74%). after the beginning of the reaction after the beginning of the reaction The toluene layer was separated concentrated the resulting residue was purified by column chromatography on silica gel

Conditions: temp:35.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: Crude 4-acetoxy-2-methyl-1-chloro-2-butene (194 g, Purity: 83.8%, 1 mol) was added to hexamethylenetetramine (168 g, 1.2 mol)/water (1 liter), and the mixture was stirred at 35° C. for 4 hours and then separated into aqueous and organic layers. 1,2-Dichloroethane (1 liter) was added to the aqueous layer, the mixture was subjected to reaction at 72° C. for 6 hours while adjusting the pH with 1N sulfuric acid. The 1,2-dichloroethane layer was separated, 1,2-dichloroethane (1 liter) was added, and the reaction was carried out again. The 1,2-dichloroethane layers were combined and concentrated. The residue was distilled under reduced pressure to give 4-acetoxy-2-methyl-2-buten-1-al (98 g, 69%). bp.0.2-0.3 : 58°-66° C. separated into aqueous and organic layers 1,2-Dichloroethane (1 liter) was added to the aqueous layer the mixture was subjected to reaction at 72° C. for 6 hours The 1,2-dichloroethane layer was separated 1,2-dichloroethane (1 liter) was added concentrated The residue was distilled under reduced pressure