2,2-dimethylcyclopentan-1-one

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 1-methyl-3,5-dinitro-2-pyridone (0.8 g, 4.0 mmol), 2,2-dimethyl-cyclopentanone (0.45 g, 4.0 mmol) and ammonia solution (2.0M) in methanol (40 mL) was refluxed overnight. The solvent was removed in vacuo and the residue was dissolved in ethyl acetate. The soluble portion was flash chromatographed over silica gel (eluent 90:10 v/v ethyl acetate-hexane) to give a yellow solid (0.183 g, 24% yield). was refluxed overnight The solvent was removed in vacuo the residue was dissolved in ethyl acetate chromatographed over silica gel (eluent 90:10 v/v ethyl acetate-hexane)

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

Procedure: The oxime of 2,2 dimethylcyclopentanone is prepared by reaction of the ketone with hydroxylamine hydrochloride in EtOH, and treated with p-toluenesulfonyl chloride and DMAP. Heating then effects Beckmann rearrangement to give 6,6-dimethyl-2-piperidinone which is deprotonated with NaH in DMF solution. Reaction with n-butyl iodide then gives the title compound. Heating

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

Procedure: The reaction and aftertreatment were conducted in the same manner as in Example 8a by using pyrazole (3.70 g, 45.1 mmol), n-butyl lithium (2.69 M solution in hexane; 17 mL, 45.7 mmol), 2,2-dimethylcyclopentanone (5.00 g, 44.6 mmol) and THF (100 mL), to yield the title compound (630 mg, 7.3%) as a colorless solid. The reaction and aftertreatment

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

Procedure: A mixture of N,N-dimethylformamide dimethyl acetal (67 mL, 503 mmol) and 2,2-dimethylcyclopentanone (10 g, 90 mmol) was heated at reflux for 2 days. The reaction mixture was then cooled down to room temperature and concentrated. Water (˜380 mL) was added to the residue, and the resulting solution was extracted with methylene chloride. The organic layer was separated, dried over MgSO4 and concentrated to give the title compound (12.5 g) as a yellow-orange oil. was heated at reflux for 2 days concentrated Water (˜380 mL) was added to the residue the resulting solution was extracted with methylene chloride The organic layer was separated dried over MgSO4 concentrated

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

Procedure: 2,2-dimethylcyclopentanone (5 g, 44.6 mmol, 1 equiv.) was dissolved in toluene (100 mL). Then, ethyl 2-cyanoacetate (5.04 g, 44.6 mmol, 1 equiv.), ammonium acetate (2.4 g, 31.2 mmol, 0.7 equiv.) and acetic acid (2.8 mL) were added in the mixture at room temperature. The mixture was refluxed for 20 hours. 10% NaCl solution (100 mL) was added in the mixture. Then, the organic layer was washed by water (50 mL) and brine (50 mL), dried by sodium sulfate and filtered. The organic layer was concentrated and the residue was purified by column chromatography to give (E)-ethyl 2-cyano-2-(2,2-dimethylcyclopentylidene)acetate (2.47 g, 32%) as a colorless oil. MS: m/z 208 (M+H)+. The mixture was refluxed for 20 hours Then, the organic layer was washed by water (50 mL) and brine (50 mL) dried by sodium sulfate filtered The organic layer was concentrated the residue was purified by column chromatography

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

Procedure: 10% aqueous sodium hydroxide solution (100 ml) is added to a mixture of 2,2-dimethylcyclopentanone (10 g) and 4-chlorobenzaldehyde (13.8 g) in ethanol (100 ml) at 0° C. After 30 minutes, a thick slurry is filtered and the solid is washed and then dried. 2,2-Dimethyl-5-(4-chlorobenzylidene)-1-cyclopentanone (12.5 g), m.p. 120° C., is obtained. This compound, dissolved in THF (50 ml), is added to a solution formed in the following manner: sodium hydride (s0% dispersion in mineral oil) (1.9 g) in anhydrous DMSO (50 ml) is heated to 80° C. until the solid has dissolved completely. The solution is then diluted with THF (100 ml) and then cooled to -10° C. A solution of trimethylsulphonium iodide (11.5 g) in dimethyl sulphoxide (80 ml) is added to the mixture in the course of 10 minutes and the mixture is stirred for 15 minutes at -10° C. A solution of 2,2-dimethyl-4-chloro-5-(4-chlorobenzylidene)-1-cyclopentanone (11.8 g) in THF (100 ml) is then added. a thick slurry is filtered the solid is washed dried

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

Procedure: A mixture of 1-methyl-3,5-dinitro-2-pyridone (0.8 g, 4.0 mmol), 2,2-dimethyl-cyclopentanone (0.45 g, 4.0 mmol) and ammonia solution (2.0M) in methanol (40 mL) was refluxed overnight. The solvent was removed in vacuo and the residue was dissolved in ethyl acetate. The soluble portion was flash chromatographed over silica gel (eluent 90:10 v/v ethyl acetate-hexane) to give a yellow solid (0.183 g, 24% yield). was refluxed overnight The solvent was removed in vacuo the residue was dissolved in ethyl acetate chromatographed over silica gel (eluent 90:10 v/v ethyl acetate-hexane)

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

Procedure: A mixture of 1-methyl-3,5-dinitro-2-pyridone (0.8 g, 4.0 mmol), 2,2-dimethyl-cyclopentanone (0.45 g, 4.0 mmol) and ammonia solution (2.0M) in methanol (40 mL) was refluxed overnight. The solvent was removed in vacuo and the residue was dissolved in ethyl acetate. The soluble portion was flash chromatographed over silica gel (eluent 90:10 v/v ethyl acetate-hexane) to give a yellow solid (0.183 g, 24% yield). was refluxed overnight The solvent was removed in vacuo the residue was dissolved in ethyl acetate chromatographed over silica gel (eluent 90:10 v/v ethyl acetate-hexane)

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

Procedure: The oxime of 2,2 dimethylcyclopentanone is prepared by reaction of the ketone with hydroxylamine hydrochloride in EtOH, and treated with p-toluenesulfonyl chloride and DMAP. Heating then effects Beckmann rearrangement to give 6,6-dimethyl-2-piperidinone which is deprotonated with NaH in DMF solution. Reaction with n-butyl iodide then gives the title compound. Heating

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

Procedure: The oxime of 2,2 dimethylcyclopentanone is prepared by reaction of the ketone with hydroxylamine hydrochloride in EtOH, and treated with p-toluenesulfonyl chloride and DMAP. Heating then effects Beckmann rearrangement to give 6,6-dimethyl-2-piperidinone which is deprotonated with NaH in DMF solution. Reaction with n-butyl iodide then gives the title compound. Heating

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

Procedure: The reaction and aftertreatment were conducted in the same manner as in Example 8a by using pyrazole (3.70 g, 45.1 mmol), n-butyl lithium (2.69 M solution in hexane; 17 mL, 45.7 mmol), 2,2-dimethylcyclopentanone (5.00 g, 44.6 mmol) and THF (100 mL), to yield the title compound (630 mg, 7.3%) as a colorless solid. The reaction and aftertreatment