tert-butyl (3R,4R)-4-azido-3-hydroxypiperidine-1-carboxylate

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

Procedure: To a stirred solution of (±)-trans-4-azido-3-hydroxy-piperidine-1-carboxylic acid tert-butyl ester (10 mmol, 2.42 g) in methanol (25 mL) was added 10% palladium on carbon (0.5 g, wet), and the resultant reaction mixture was subjected to hydrogenation using a balloon full of hydrogen for 8 h. The catalyst was filtered through a pad of celite, and the pad was with methanol (25 mL). The combined filtrate was concentrated under reduced pressure to provide (±)-trans-4-amino-3-hydroxy-piperidine-1-carboxylic acid tert-butyl ester. the resultant reaction mixture for 8 h The catalyst was filtered through a pad of celite The combined filtrate was concentrated under reduced pressure

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

Procedure: To a stirred solution of 7-oxa-3-aza-bicyclo[4.1.0]heptane-3-carboxylic acid tert-butyl ester (15.5 mmol, 3.1 g) in DMF (25 mL) was added a solution of sodium azide (23.3 mmol, 1.5 g) in acetone-water (2:1, 30 mL) (WO 2005/066176). The reaction mixture was heated at 80° C. for 12 h. The reaction mixture was cooled to room temperature, and EtOAc (100 mL) was added. The organic layer was washed with water and brine, dried (Na2SO4), filtered and concentrated under reduced pressure. The residue was purified on a SiO2 cartridge (5% EtOAc in hexane -25% EtOAc in hexane) to provide (±)-trans-4-azido-3-hydroxy-piperidine-1-carboxylic acid tert-butyl ester (2.3 g) (faster moving compound) 1H NMR (400 MHz, CDCl3) δ 4.12 (1H, dd), 3.95 (1H, bs), 3.50 (1H, bs), 3.30-3.42 (1H, m), 2.90 (1H, bs), 2.79 (1H, dd), 2.30-2.70 (1H, bs), 1.96-2.05 (1H, m), 1.48-1.6 (1H, m), 1.46 (9H, s). and (±)-trans-3-azido-4-hydroxy-piperidine-1-carboxylic acid tert-butyl ester (0.57 g) (slower moving compound) 1H NMR (400 MHz, CDCl3) δ 4.21 (1H, bs), 4.00 (1H, d), 3.56 (1H, bs), 3.21-3.35 (1H, m), 2.55-2.95 (2H, m), 2.24 (1H, bs), 1.92-2.04 (1H, m), 1.49-1.6 (1H, m), 1.47 (9H, s) The reaction mixture was cooled to room temperature The organic layer was washed with water and brine dried (Na2SO4) filtered concentrated under reduced pressure The residue was purified on a SiO2 cartridge (5% EtOAc in hexane -25% EtOAc in hexane)

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

Procedure: To a stirred solution of (±)-trans-4-azido-3-hydroxy-piperidine-1-carboxylic acid tert-butyl ester (10 mmol, 2.42 g) in methanol (25 mL) was added 10% palladium on carbon (0.5 g, wet), and the resultant reaction mixture was subjected to hydrogenation using a balloon full of hydrogen for 8 h. The catalyst was filtered through a pad of celite, and the pad was with methanol (25 mL). The combined filtrate was concentrated under reduced pressure to provide (±)-trans-4-amino-3-hydroxy-piperidine-1-carboxylic acid tert-butyl ester. the resultant reaction mixture for 8 h The catalyst was filtered through a pad of celite The combined filtrate was concentrated under reduced pressure

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

Procedure: To a stirred solution of 7-oxa-3-aza-bicyclo[4.1.0]heptane-3-carboxylic acid tert-butyl ester (15.5 mmol, 3.1 g) in DMF (25 mL) was added a solution of sodium azide (23.3 mmol, 1.5 g) in acetone-water (2:1, 30 mL) (WO 2005/066176). The reaction mixture was heated at 80° C. for 12 h. The reaction mixture was cooled to room temperature, and EtOAc (100 mL) was added. The organic layer was washed with water and brine, dried (Na2SO4), filtered and concentrated under reduced pressure. The residue was purified on a SiO2 cartridge (5% EtOAc in hexane -25% EtOAc in hexane) to provide (±)-trans-4-azido-3-hydroxy-piperidine-1-carboxylic acid tert-butyl ester (2.3 g) (faster moving compound) 1H NMR (400 MHz, CDCl3) δ 4.12 (1H, dd), 3.95 (1H, bs), 3.50 (1H, bs), 3.30-3.42 (1H, m), 2.90 (1H, bs), 2.79 (1H, dd), 2.30-2.70 (1H, bs), 1.96-2.05 (1H, m), 1.48-1.6 (1H, m), 1.46 (9H, s). and (±)-trans-3-azido-4-hydroxy-piperidine-1-carboxylic acid tert-butyl ester (0.57 g) (slower moving compound) 1H NMR (400 MHz, CDCl3) δ 4.21 (1H, bs), 4.00 (1H, d), 3.56 (1H, bs), 3.21-3.35 (1H, m), 2.55-2.95 (2H, m), 2.24 (1H, bs), 1.92-2.04 (1H, m), 1.49-1.6 (1H, m), 1.47 (9H, s) The reaction mixture was cooled to room temperature The organic layer was washed with water and brine dried (Na2SO4) filtered concentrated under reduced pressure The residue was purified on a SiO2 cartridge (5% EtOAc in hexane -25% EtOAc in hexane)

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

Procedure: To a stirred solution of (±)-trans-4-azido-3-hydroxy-piperidine-1-carboxylic acid tert-butyl ester (10 mmol, 2.42 g) in methanol (25 mL) was added 10% palladium on carbon (0.5 g, wet), and the resultant reaction mixture was subjected to hydrogenation using a balloon full of hydrogen for 8 h. The catalyst was filtered through a pad of celite, and the pad was with methanol (25 mL). The combined filtrate was concentrated under reduced pressure to provide (±)-trans-4-amino-3-hydroxy-piperidine-1-carboxylic acid tert-butyl ester. the resultant reaction mixture for 8 h The catalyst was filtered through a pad of celite The combined filtrate was concentrated under reduced pressure

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

Procedure: To a stirred solution of 7-oxa-3-aza-bicyclo[4.1.0]heptane-3-carboxylic acid tert-butyl ester (15.5 mmol, 3.1 g) in DMF (25 mL) was added a solution of sodium azide (23.3 mmol, 1.5 g) in acetone-water (2:1, 30 mL) (WO 2005/066176). The reaction mixture was heated at 80° C. for 12 h. The reaction mixture was cooled to room temperature, and EtOAc (100 mL) was added. The organic layer was washed with water and brine, dried (Na2SO4), filtered and concentrated under reduced pressure. The residue was purified on a SiO2 cartridge (5% EtOAc in hexane-25% EtOAc in hexane) to provide (±)-trans-4-azido-3-hydroxy-piperidine-1-carboxylic acid tert-butyl ester (2.3 g) (faster moving compound) 1H NMR (400 MHz, CDCl3) δ 4.12 (1 H, dd), 3.95 (1 H, bs), 3.50 (1 H, bs), 3.30-3.42 (1 H, m), 2.90 (1 H, bs), 2.79 (1 H, dd), 2.30-2.70 (1 H, bs), 1.96-2.05 (1 H, m), 1.48-1.6 (1 H, m), 1.46 (9 H, s). and (±)-trans-3-azido-4-hydroxy-piperidine-1-carboxylic acid tert-butyl ester (0.57 g) (slower moving compound) 1H NMR (400 MHz, CDCl3) δ 4.21 (1 H, bs), 4.00 (1 H, d), 3.56 (1 H, bs), 3.21-3.35 (1 H, m), 2.55-2.95 (2 H, m), 2.24 (1 H, bs), 1.92-2.04 (1 H, m), 1.49-1.6 (1 H, m), 1.47 (9 H, s) The reaction mixture was cooled to room temperature The organic layer was washed with water and brine dried (Na2SO4) filtered concentrated under reduced pressure The residue was purified on a SiO2 cartridge (5% EtOAc in hexane-25% EtOAc in hexane)

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

Procedure: A solution of (3R*,4R*)-4-azido-3-hydroxy-piperidine-1-carboxylic acid tert-butyl ester (2.96 g, 12.23 mmol) in ethanol (50 mL) was flushed out with nitrogen. Palladium (10 wt % on activated carbon) (˜300 mg) was added and the mixture flushed out with hydrogen and then stirred under a hydrogen balloon at room temperature overnight. The reaction mixture was filtered through celite and the filtrate evaporated to give (3R*,4R*)-4-amino-3-hydroxy-piperidine-1-carboxylic acid tert-butyl ester (2.73 g). the mixture flushed out with hydrogen The reaction mixture was filtered through celite the filtrate evaporated

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

Procedure: To a stirring solution of (±)-7-oxa-3-aza-bicyclo[4.1.0]heptane-3-carboxylic acid tert-butyl ester (2.4 g, 12.06 mmol) in ethanol (20 mL) was added sodium azide (1.00 g, 15.62 mmol) and ammonium chloride (840 mg, 15.79 mmol). The resulting mixture was heated to reflux overnight and then partitioned between ethyl acetate and water. The combined organic layers were washed with brine, separated and dried (MgSO4). The crude product was purified by column chromatography to yield (3R*,4R*)-4-azido-3-hydroxy-piperidine-1-carboxylic acid tert-butyl ester (1.95 g) and (3S*,4S*)-3-azido-4-hydroxy-piperidine-1-carboxylic acid tert-butyl ester (312 mg). The resulting mixture was heated to reflux overnight partitioned between ethyl acetate and water The combined organic layers were washed with brine separated dried (MgSO4) The crude product was purified by column chromatography

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

Procedure: To a stirred solution of (±)-trans-4-azido-3-hydroxy-piperidine-1-carboxylic acid tert-butyl ester (10 mmol, 2.42 g) in methanol (25 mL) was added 10% palladium on carbon (0.5 g, wet), and the resultant reaction mixture was subjected to hydrogenation using a balloon full of hydrogen for 8 h. The catalyst was filtered through a pad of celite, and the pad was with methanol (25 mL). The combined filtrate was concentrated under reduced pressure to provide (±)-trans-4-amino-3-hydroxy-piperidine-1-carboxylic acid tert-butyl ester. the resultant reaction mixture for 8 h The catalyst was filtered through a pad of celite The combined filtrate was concentrated under reduced pressure

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

Procedure: To a stirred solution of 7-oxa-3-aza-bicyclo[4.1.0]heptane-3-carboxylic acid tert-butyl ester (15.5 mmol, 3.1 g) in DMF (25 mL) was added a solution of sodium azide (23.3 mmol, 1.5 g) in acetone-water (2:1, 30 mL) (WO 2005/066176). The reaction mixture was heated at 80° C. for 12 h. The reaction mixture was cooled to room temperature, and EtOAc (100 mL) was added. The organic layer was washed with water and brine, dried (Na2SO4), filtered and concentrated under reduced pressure. The residue was purified on a SiO2 cartridge (5% EtOAc in hexane -25% EtOAc in hexane) to provide (±)-trans-4-azido-3-hydroxy-piperidine-1-carboxylic acid tert-butyl ester (2.3 g)(faster moving compound) 1H NMR (400 MHz, CDCl3) δ 4.12 (1H, dd), 3.95 (1H, bs), 3.50 (1H, bs), 3.30-3.42 (1H, m), 2.90 (1H, bs), 2.79 (1H, dd), 2.30-2.70 (1H, bs), 1.96-2.05 (1H, m), 1.48-1.6 (1H, m), 1.46 (9H, s). and (±)-trans-3-azido-4-hydroxy-piperidine-1-carboxylic acid tert-butyl ester (0.57 g) (slower moving compound) 1H NMR (400 MHz, CDCl3) δ 4.21 (1H, bs), 4.00 (1H, d), 3.56 (1H, bs), 3.21-3.35 (1H, m), 2.55-2.95 (2H, m), 2.24 (1H, bs), 1.92-2.04 (1H, m), 1.49-1.6 (1H, m), 1.47 (9H, s) The reaction mixture was cooled to room temperature The organic layer was washed with water and brine dried (Na2SO4) filtered concentrated under reduced pressure The residue was purified on a SiO2 cartridge (5% EtOAc in hexane -25% EtOAc in hexane)

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

Procedure: Dissolve racemic trans-4-azido-3-hydroxy-piperidine-1-carboxylic acid tert-butyl ester (0.23 mol, 56.6 g) in methanol (500 mL), add 10% palladium on carbon (12.0 g) and hydrogenate (1 atm) at room temperature for 16 h. Filter off the catalyst through a plug of diatomaceous earth and concentrate the filtrate to obtain the title compound (53.7 g, 99%) as a thick, light yellow oil. Filter off the catalyst through a plug of diatomaceous earth concentrate the filtrate

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

Procedure: Heat a mixture of racemic trans-7-oxa-3-aza-bicyclo[4.1.0]heptane-3-carboxylic acid tert-butyl ester (0.56 mol, 112 g), sodium azide (1.12 mol, 73.08 g), ammonium chloride (0.56 mol, 30.07 g) and methanol/water (3:1) (1 L) at 65° C. for 16 h. Dilute the reaction mixture with water, extract with dichloromethane, and wash the organic layer with saturated sodium bicarbonate and brine solution. Dry the organic layer over anhydrous sodium sulfate, filter, and concentrate. Purify the residue on a silica gel column using 6% ethyl acetate in hexanes as eluent to obtain the title compound (42.3 g, 42%) as a light yellow oil. 1H NMR (400 MHz, CDCl3) δ 1.48 (s, 9H), 1.84 (br s 1H), 1.97-2.01 (m, 1H), 2.74-2.82 (m, 1H), 2.88 (br s, 1H), 3.37-3.40 (m, 1H), 3.50 (br s, 1H), 3.91 (br s, 1H), 4.09 (dd, 1H). ES-MS m/z 143 [M−Boc]+. Heat extract with dichloromethane wash the organic layer with saturated sodium bicarbonate and brine solution Dry the organic layer over anhydrous sodium sulfate filter concentrate Purify the residue on a silica gel column