ethyl 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:

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: 51.93 g of sodium hydride (60% dispersion in oil) is taken up in 1100 ml of dry dimethyl sulphoxide under argon. 272 g of trimethylsulphoxonium iodide are added in portions over 20 minutes at room temperature, and the reaction mixture is then stirred at room temperature for 1.5 hours. 170.00 g of ethyl (tetrahydropyran-4-ylidene)acetate [130312-00-4] are added dropwise, and the reaction mixture is stirred at room temperature for 18 hours. The mixture is poured into ice and extracted with tert-butyl methyl ether. The combined organic extracts are washed with brine, dried with sodium sulphate and evaporated. The title compound is obtained as a colourless oil from the residue by vacuum distillation (68-70° C., 0.09 mbar). Rt=3.49 (Gradient I). the reaction mixture is stirred at room temperature for 18 hours The mixture is poured into ice extracted with tert-butyl methyl ether The combined organic extracts are washed with brine dried with sodium sulphate evaporated

Conditions: temp:70.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: To a mixture composed of ethyl 2-(2H-pyran-4(3H,5H,6H)-ylidene)acetate (10 g, 58.75 mmol) and ammonium formate (37 g, 587.54 mmol) in methanol (150 ml) was added 10% Pd-carbon (1.0 g) at room temperature, and the mixture was stirred at 70° C. for 15 hr. The reaction mixture was allowed to cool to room temperature, and the catalyst was collected by filtration through Celite pad and was washed with methanol. The filtrate was concentrated under reduced pressure, and the residue was chromatographed on silica gel column (hexane:ethyl acetate=94:6) to give the title compound as an oil (7.9 g, yield 78%). to cool to room temperature the catalyst was collected by filtration through Celite pad was washed with methanol The filtrate was concentrated under reduced pressure the residue was chromatographed on silica gel column (hexane:ethyl acetate=94:6)

Conditions: temp:80.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: Triethyl phosphonoacetate (22.6 g, 99.88 mmol) was added to a solution of dihydro-2H-pyran-4(3H)-one (10.0 g, 99.88 mmol) in DMF (100 ml) at room temperature, and the mixture was stirred at 80° C. for 15 hr. The mixture was allowed to cool to room temperature, was diluted with water, and was extracted with ether. The organic layer was washed with water and saturated brine, was dried over anhydrous magnesium sulfate, and the filtrate was concentrated under reduced pressure. The residue was chromatographed on silica gel column (hexane:ethyl acetate=95:5) to give the title compound as a yellow oil (13.2 g, yield 78%). to cool to room temperature was extracted with ether The organic layer was washed with water and saturated brine was dried over anhydrous magnesium sulfate the filtrate was concentrated under reduced pressure The residue was chromatographed on silica gel column (hexane:ethyl acetate=95:5)

Conditions: temp:80.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: Triethyl phosphonoacetate (22.6 g, 99.88 mmol) was added to a solution of dihydro-2H-pyran-4(3H)-one (10.0 g, 99.88 mmol) in DMF (100 ml) at room temperature, and the mixture was stirred at 80° C. for 15 hr. The mixture was allowed to cool to room temperature, was diluted with water, and was extracted with ether. The organic layer was washed with water and saturated brine, was dried over anhydrous magnesium sulfate, and the filtrate was concentrated under reduced pressure. The residue was chromatographed on silica gel column (hexane:ethyl acetate=95:5) to give the title compound as a yellow oil (13.2 g, yield 78%). to cool to room temperature was extracted with ether The organic layer was washed with water and saturated brine was dried over anhydrous magnesium sulfate the filtrate was concentrated under reduced pressure The residue was chromatographed on silica gel column (hexane:ethyl acetate=95:5)

Conditions: temp:50.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: To a solution of tetrahydro-4H-pyran-4-one (5.0 g, 50 mmol) in 150 mL toluene at ambient temperature was added carbethoxymethylenetriphenyl phosphorane (17.4 g, 50 mmoL). The mixture was warmed to 50° C. and allowed to stir for 16 h. The mixture was cooled to ambient temperature, concentrated under reduced pressure and purified by column chromatography (Si2O, 50% hexanes in EtOAc) to provide the title compound (2.2 g, 13 mmol, 26% yield). MS (DCI/NH3) m/z 171 (M+H)+. The mixture was cooled to ambient temperature concentrated under reduced pressure purified by column chromatography (Si2O, 50% hexanes in EtOAc)

Conditions: temp:50.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: To a solution of tetrahydro-4H-pyran-4-one (5.0 g, 50 mmol) in 150 mL toluene at ambient temperature was added carbethoxymethylenetriphenyl phosphorane (17.4 g, 50 mmoL). The mixture was warmed to 50° C. and allowed to stir for 16 h. The mixture was cooled to ambient temperature, concentrated under reduced pressure and purified by column chromatography (Si2O, 50% hexanes in EtOAc) to provide the title compound (2.2 g, 13 mmol, 26% yield). MS (DCI/NH3) m/z 171 (M+H)+. The mixture was cooled to ambient temperature concentrated under reduced pressure purified by column chromatography (Si2O, 50% hexanes in EtOAc)