tert-butyl (2R)-2-formylpyrrolidine-1-carboxylate

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

Procedure: (R)-N-Boc-2-Ethynyl-pyrrolidine was prepared according to Method X above by the treatment of (R)-N-Boc-2-formyl-pyrrolidine (700 mg, 3.51 mmol) (Example 89A) with potassium tert-butoxide (510 mg, 4.56 mmol) and diazomethyl-phosphonic-acid-diethylester (820 mg, 4.56 mmol) (also prepared according to Method X). (R)-N-Boc-2-Ethynyl-pyrrolidine was obtained after silica gel cotoumn chromatography with 10% Et2O in hexanes. (Yield 150 mg, 25%). (R)-N-Boc-2-Ethynyl-pyrrolidine was prepared also prepared

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

Procedure: (R)-N-Boc-2-Formyl-pyrrolidine was prepared by Swern oxidation of (R)-N-Boc prolinol (Fluka) using the procedure for the oxidation of CBZ-prolinol described by of M. G. B. Drew et al. supra.

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

Procedure: (R)-N-Boc-2-Ethynyl-pyrrolidine was prepared according to Method X above by the treatment of (R)-N-Boc-2-formyl-pyrrolidine (700 mg, 3.51 mmol) (Example 89A) with potassium tert-butoxide (510 mg, 4.56 mmol) and diazomethyl-phosphonic-acid-diethylester (820 mg, 4.56 mmol) (also prepared according to Method X). (R)-N-Boc-2-Ethynyl-pyrrolidine was obtained after silica gel coloumn chromatography with 10% Et2O in hexanes. (Yield 150 mg, 25%). (R)-N-Boc-2-Ethynyl-pyrrolidine was prepared also prepared

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

Procedure: (R)-N-Boc-2-Formyl-pyrrolidine was prepared by Swern oxidation of (R)-N-Boc prolinol (Fluka) using the procedure for the oxidation of CBZ-prolinol described by of M. G. B. Drew et al. supra.

Conditions: temp:25.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: To a water cooled (25° C.) solution of 10.0 g of (R)-2-(hydroxymethyl)-1-pyrrolidinecarboxylic acid, 1,1-dimethylethyl ester in 250 ml of dry methylene chloride is added in one portion 16.0 g of pyridinium chlorochromate, 36.0 g of dried, crushed 4Å molecular sieves and 4.5 ml of glacial acetic acid. The resulting mixture is stirred at 25° C. for one hour. Twenty-five grams of diatomaceous earth and 500 ml of diethyl ether is added, the suspension is filtered through a pad of diatomaceous earth and the filtrate concentrated in vacuo. The residue is dissolved in diethyl ether and is passed through a short column of silica gel using diethyl ether as the eluant. The first two 500 ml fractions contain the desired aldehyde. The solvent is concentrated in vacuo to give 10.1 g of desired product. 36.0 g of dried crushed 4Å molecular sieves and 4.5 ml of glacial acetic acid Twenty-five grams of diatomaceous earth and 500 ml of diethyl ether is added the suspension is filtered through a pad of diatomaceous earth the filtrate concentrated in vacuo The residue is dissolved in diethyl ether The solvent is concentrated in vacuo

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

Procedure: In accordance with Scheme I, N-α-t-BOC-D-proline 2a is reacted in an ether solvent such as tetrahydrofuran at a temperature ranging from -2° C. to the reflux temperature of the solvent with 10M borane-methyl sulfide complex to produce (R)-2-(hydroxymethyl)-1pyrrolidinecarboxylic acid, 1,1-dimethylethyl ester 3a. Compound 3a in a chlorinated hydrocarbon solvent such as methylene chloride is treated with an oxidizing agent such as pyridinium chlorochromate, 4Å molecular sieves and glacial acetic acid to give (R)-2-formyl-1-pyrrolidinecarboxylic acid 1,1-dimethylethyl ester 4a. Compound 4a in methylene chloride is treated with a methylene chloride solution of triphenylphosphine and carbon tetrabromide to produce (R)-2-(2,2-dibromoethenyl)-1pyrrolidinecarboxylic acid, 1,1-dimethylethyl ester 5a. The dibromo compound 5a in an ether solvent such as tetrahydrofuran is reacted at -78° C. with an alkyl lithium reagent such as sec-butyllithium to give (R)-2-ethynyl-1-pyrrolidinecarboxylic acid, 1,1-dimethylethyl ester 6a.

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

Procedure: In accordance with Scheme I, N-α-t-BOC-D-proline 2a is reacted in an ether solvent such as tetrahydrofuran at a temperature ranging from -2° C. to the reflux temperature of the solvent with 10M borane-methyl sulfide complex to produce (R)-2-(hydroxymethyl)-1pyrrolidinecarboxylic acid, 1,1-dimethylethyl ester 3a. Compound 3a in a chlorinated hydrocarbon solvent such as methylene chloride is treated with an oxidizing agent such as pyridinium chlorochromate, 4Å molecular sieves and glacial acetic acid to give (R)-2-formyl-1-pyrrolidinecarboxylic acid 1,1-dimethylethyl ester 4a. Compound 4a in methylene chloride is treated with a methylene chloride solution of triphenylphosphine and carbon tetrabromide to produce (R)-2-(2,2-dibromoethenyl)-1pyrrolidinecarboxylic acid, 1,1-dimethylethyl ester 5a. The dibromo compound 5a in an ether solvent such as tetrahydrofuran is reacted at -78° C. with an alkyl lithium reagent such as sec-butyllithium to give (R)-2-ethynyl-1-pyrrolidinecarboxylic acid, 1,1-dimethylethyl ester 6a.

Conditions: temp:-78.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: n-Butyl lithium (1.6 M in hexanes) (27 mL, 43 mmol) was added to ice-cold hexamethyldisilazane (9.2 mL, 44 mmol) under a nitrogen atmosphere. The solution was stirred for 10 min and was then added to a suspension of methyl(triphenylphosphonium)bromide (15.5 g, 43 mmol) in 100 mL of THF at ambient temperature. After stirring for 1 h, the mixture was cooled to −78° C. and a solution of tert-butyl (2R)-2-formylpyrrolidine-1-carboxylate (7.9 g, 40 mmol) in 50 mL of THF was added. The cold bath was removed and the mixture stirred overnight at ambient temperature. The reaction mixture was then quenched with saturated NH4Cl, the phases were separated, and the organic phase was washed with saturated NH4Cl, brine, dried over Na2SO4, filtered, and concentrated to give an orange oil. The oil was purified on a Biotage 40M column eluting with heptane to give tert-butyl (2R)-2-vinylpyrrolidine-1-carboxylate (5.0 g). After stirring for 1 h The cold bath was removed the mixture stirred overnight at ambient temperature The reaction mixture was then quenched with saturated NH4Cl the phases were separated the organic phase was washed with saturated NH4Cl, brine dried over Na2SO4 filtered concentrated to give an orange oil The oil was purified on a Biotage 40M column eluting with heptane

Conditions: temp:-78.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: Oxalyl chloride (9.0 mL, 100 mmol) was added to a solution of DMSO (10.5 mL, 150 mmol) in 80 mL of CH2Cl2 at −78° C., under a nitrogen atmosphere. The solution was stirred for 20 min at −78° C., tert-butyl (2R)-2-(hydroxymethyl)pyrrolidine-1-carboxylate (9.9 g, 49 mmol) was added, and the resultant solution stirred at −78° C. for 20 min. Triethylamine (28 mL, 200 mmol) was added to the reaction solution, the dry ice-acetone bath was removed, and the resultant solution was allowed to stir for two hours, slowly warming to ambient temperature. The reaction solution was quenched with brine, the phases were separated, and the organic phase was washed with 1 M KH2PO4 and saturated NaHCO3. The organic solution was then dried over Na2SO4, filtered, and concentrated to an orange oil. This oil was then dissolved in heptane, filtered through a plug of silica gel eluting with heptane, and the filtrate was concentrated to yield tert-butyl (2R)-2-formylpyrrolidine-1-carboxylate (7.87 g). the dry ice-acetone bath was removed to stir for two hours slowly warming to ambient temperature The reaction solution was quenched with brine the phases were separated the organic phase was washed with 1 M KH2PO4 and saturated NaHCO3 The organic solution was then dried over Na2SO4 filtered concentrated to an orange oil This oil was then dissolved in heptane filtered through a plug of silica gel eluting with heptane the filtrate was concentrated

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

Procedure: The compound (53.8 mg) obtained in Example 1-4 was dissolved in methanol (0.8 ml). Then, the solution was added with trimethyl orthoformate (50 μl), acetic acid (50 μl), N-Boc-D-prolinal (manufactured by Aldrich Corporation) (25.7 mg) and stirred at room temperature for 10 minutes. Subsequently, sodium cyanoborohydride (24.4 mg) was added, followed by stirring overnight at room temperature. The solvent was distilled off under reduced pressure and the residue was then dissolved in chloroform, followed by washing with 1 mol/l sodium hydroxide and saturated saline solution and drying with anhydrous sodium sulfate. After filtration, the solvent was distilled off under reduced pressure and the residue was then purified through silica gel column chromatography (chloroform/methanol). Then, the purified product was dissolved in methanol (500 μl) and added with a 4 mol/l hydrogen chloride/dioxane solution (500 μl), followed by stirring at room temperature for 2 hours. After completion of the reaction, the solvent was distilled off under reduced pressure and the residue was then purified through silica gel column chromatography (chloroform/methanol), thereby obtaining hydrochloride (33.9 mg) of the subject compound as a white solid. by stirring overnight at room temperature The solvent was distilled off under reduced pressure the residue was then dissolved in chloroform by washing with 1 mol/l sodium hydroxide and saturated saline solution drying with anhydrous sodium sulfate After filtration the solvent was distilled off under reduced pressure the residue was then purified through silica gel column chromatography (chloroform/methanol) Then, the purified product was dissolved in methanol (500 μl) added with a 4 mol/l hydrogen chloride/dioxane solution (500 μl) by stirring at room temperature for 2 hours After completion of the reaction the solvent was distilled off under reduced pressure the residue was then purified through silica gel column chromatography (chloroform/methanol)

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

Procedure: Prepared from L-prolinol using the procedure described for Intermediate 2.

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

Procedure: (R)-N-Boc-2-Ethynyl-pyrrolidine was prepared according to Method X above by the treatment of (R)-N-Boc-2-formyl-pyrrolidine (700 mg, 3.51 mmol) (Example 89A) with potassium tert-butoxide (510 mg, 4.56 mmol) and diazomethyl-phosphonic-acid-diethylester (820 mg, 4.56 mmol) (also prepared according to Method X). (R)-N-Boc-2-Ethynyl-pyrrolidine was obtained after silica gel coloumn chromatography with 10% Et2O in hexanes. (Yield 150 mg, 25%). (R)-N-Boc-2-Ethynyl-pyrrolidine was prepared also prepared