ethyl 2-cyano-2-(oxan-4-ylidene)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:; See reaction.notes.procedure_details.

Procedure: A mixture of tetrahydropyran-4-one (12 g), ethyl cyanoacetate (13.6 g), ammonium acetate (1.2 g), glacial acetic acid (2.4 ml) and toluene (15 ml) is stirred at reflux for 16 hours. The mixture is diluted with toluene and the organic layer is separated, washed with water, then brine, and dried over magnesium sulfate. It is concentrated at reduced pressure to an oil which solidifies. It is further purified by flash chromatography through silica gel with methylene chloride as eluent. The desired fractions are combined and concentrated to dryness at reduced pressure to afford 4-(alpha-ethoxycarbonyl-cyanomethylene)-tetrahydropyran. at reflux for 16 hours the organic layer is separated washed with water brine, and dried over magnesium sulfate It is concentrated at reduced pressure to an oil which It is further purified by flash chromatography through silica gel with methylene chloride as eluent concentrated to dryness at reduced pressure

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

Procedure: A mixture of tetrahydropyran-4-one (12 g), ethyl cyanoacetate (13.6 g), ammonium acetate (1.2 g), glacial acetic acid (2.4 ml) and toluene (15 ml) is stirred at reflux for 16 hours. The mixture is diluted with toluene and the organic layer is separated, washed with water, then brine, and dried over magnesium sulfate. It is concentrated at reduced pressure to an oil which solidifies. It is further purified by flash chromatography through silica gel with methylene chloride as eluent. The desired fractions are combined and concentrated to dryness at reduced pressure to afford 4-(alpha-ethoxycarbonyl-cyanomethylene)-tetrahydropyran. at reflux for 16 hours the organic layer is separated washed with water brine, and dried over magnesium sulfate It is concentrated at reduced pressure to an oil which It is further purified by flash chromatography through silica gel with methylene chloride as eluent concentrated to dryness at reduced pressure

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

Procedure: A stirred solution of tetrahydro-pyran-4-one (5 g) in toluene (50 mL) was treated sequentially with cyano-acetic acid ethyl ester (5.3 mL), ammonium acetate (0.7 g), acetic acid (2.2 mL) and piperidine (3 drops) then stirred at reflux temperature for 3.5 hours and then stood at room temperature for 3 days. The reaction mixture was evaporated to give a red oil, which solidified on standing at room temperature. This solid was treated with water (30 mL) and the mixture was extracted with ethyl acetate (50 mL). The extract was washed with saturated aqueous sodium bicarbonate solution (30 mL), then with water (30 mL), then dried over magnesium sulfate and then evaporated. The residual pale yellow waxy solid (8.92 g) was refluxed with petroleum ether (b.p. 80–100° C.) when partial solution was achieved. This mixture was treated with cyclohexane (20 mL) and then decanted to remove a small amount of brown gum. The decanted solution was stood at room temperature overnight and the resulting crystalline pale yellow solid was filtered then washed with pentane and then dried at 40° C. under vacuum to give the title compound (5.10 g) as a pale yellow crystalline solid. LC-MS: RT=2.85 minutes, MS(ES+): 169(M+H)+, MS(ES−): 194(M−H)−. at reflux temperature for 3.5 hours The reaction mixture was evaporated to give a red oil, which on standing at room temperature the mixture was extracted with ethyl acetate (50 mL) The extract was washed with saturated aqueous sodium bicarbonate solution (30 mL) with water (30 mL), then dried over magnesium sulfate evaporated The residual pale yellow waxy solid (8.92 g) was refluxed with petroleum ether (b.p. 80–100° C.) when partial solution This mixture was treated with cyclohexane (20 mL) decanted to remove a small amount of brown gum The decanted solution was stood at room temperature overnight the resulting crystalline pale yellow solid was filtered then washed with pentane dried at 40° C. under vacuum

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

Procedure: A mixture of tetrahydropyran-4-one (12 g), ethyl cyanoacetate (13.6 g), ammonium acetate (1.2 g), glacial acetic acid (2.4 ml) and toluene (15 ml) is stirred at reflux for 16 hours. The mixture is diluted with toluene and the organic layer is separated, washed with water, then brine, and dried over magnesium sulfate. It is concentrated at reduced pressure to an oil which solidifies. It is further purified by flash chromatography through silica gel with methylene chloride as eluent. The desired fractions are combined and concentrated to dryness at reduced pressure to afford 4-(alpha-ethoxycarbonyl-cyanomethylene)-tetrahydropyran. at reflux for 16 hours the organic layer is separated washed with water brine, and dried over magnesium sulfate It is concentrated at reduced pressure to an oil which It is further purified by flash chromatography through silica gel with methylene chloride as eluent concentrated to dryness at reduced pressure