tert-butyl (1R,3S,4S)-3-(hydroxymethyl)-2-azabicyclo[2.2.1]heptane-2-carboxylate

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

Procedure: To a cold (−60° C.) solution of oxalyl chloride (60.8 mmol) in dry DCM (130 mL) is added dropwise DMSO (111 mmol) within 5 min. After 15 min a solution of (1R,3S,4S)-3-hydroxymethyl-2-aza-bicyclo[2.2.1]heptane-2-carboxylic acid tert-butyl ester (50.7 mmol) in dry DCM (40 mL) is added dropwise within 15 min. Stirring is continued for 45 min at −55° C., then DIPEA (253 mmol; dried over 3 A molecular sieve) is added during 5 min. The reaction mixture is allowed to reach rt and diluted with water (250 mL). The layers are separated and the organic layer is washed twice with aq. citric acid (5%, 200 mL each) and twice with brine. The combined organic layers are dried over MgSO4 and concentrated in vacuo to give the desired product which is used without further purification. 1H-NMR (CDCl3, 2 rotamers): δ=1.31-1.37 (m, 1H); 1.44 & 1.50 (2 s, 9H); 1.58-1.84 (m, 5H); 2.78 & 2.81 (2 bs, 1H); 3.60 & 3.74 (2 bs, 1H); 4.26 & 4.41 (2 bs, 1H); 9.55 & 9.60 (2 bs, 1H). dried over 3 A molecular sieve) is added during 5 min to reach rt diluted with water (250 mL) The layers are separated the organic layer is washed twice with aq. citric acid (5%, 200 mL each) and twice with brine The combined organic layers are dried over MgSO4 concentrated in vacuo

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

Procedure: At −78° C. a solution of DIBAL in toluene (1.7M, 137 mmol) is added dropwise to a solution of (1R,3S,4S)-2-aza-bicyclo[2.2.1]heptane-2,3-dicarboxylic acid 2-tert-butyl ester 3-methyl ester (61.0 mmol) in THF (180 mL). After 80 min the solution is allowed to reach rt, stirred for additional 2 h and poured into a mixture of aq. NaOH solution (1.0M, 200 mL) and ice. EtOAc (150 mL) is added, the layers are separated and the aq. layer is extracted three times with EtOAc (150 mL each). The combined organic layers are washed with aq. NaOH solution (1.0M) and brine, dried over Na2SO4 and concentrated in vacuo to give a crude product which is used without further purification. LC-MS (basic): tR=0.78 min; [M+H]+=228.3. to reach rt the layers are separated the aq. layer is extracted three times with EtOAc (150 mL each) The combined organic layers are washed with aq. NaOH solution (1.0M) and brine dried over Na2SO4 concentrated in vacuo

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

Procedure: At −78° C. a solution of DIBAL in toluene (1.7M, 137 mmol) is added dropwise to a solution of (1R,3S,4S)-2-aza-bicyclo[2.2.1]heptane-2,3-dicarboxylic acid 2-tert-butyl ester 3-methyl ester (61.0 mmol) in THF (180 mL). After 80 min the solution is allowed to reach rt, stirred for additional 2 h and poured into a mixture of aq. NaOH solution (1.0M, 200 mL) and ice. EtOAc (150 mL) is added, the layers are separated and the aq. layer is extracted three times with EtOAc (150 mL each). The combined organic layers are washed with aq. NaOH solution (1.0M) and brine, dried over Na2SO4 and concentrated in vacuo to give a crude product which is used without further purification. LC-MS (basic): tR=0.78 min; [M+H]+=228.3. to reach rt the layers are separated the aq. layer is extracted three times with EtOAc (150 mL each) The combined organic layers are washed with aq. NaOH solution (1.0M) and brine dried over Na2SO4 concentrated in vacuo

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

Procedure: To a cold (−60° C.) solution of oxalyl chloride (60.8 mmol) in dry DCM (130 mL) is added dropwise DMSO (111 mmol) within 5 min. After 15 min a solution of (1R,3S,4S)-3-hydroxymethyl-2-aza-bicyclo[2.2.1]heptane-2-carboxylic acid tert-butyl ester (50.7 mmol) in dry DCM (40 mL) is added dropwise within 15 min. Stirring is continued for 45 min at −55° C., then DIPEA (253 mmol; dried over 3 A molecular sieve) is added during 5 min. The reaction mixture is allowed to reach rt and diluted with water (250 mL). The layers are separated and the organic layer is washed twice with aq. citric acid (5%, 200 mL each) and twice with brine. The combined organic layers are dried over MgSO4 and concentrated in vacuo to give the desired product which is used without further purification. 1H-NMR (CDCl3, 2 rotamers): δ=1.31-1.37 (m, 1H); 1.44 & 1.50 (2 s, 9H); 1.58-1.84 (m, 5H); 2.78 & 2.81 (2 bs, 1H); 3.60 & 3.74 (2 bs, 1H); 4.26 & 4.41 (2 bs, 1H); 9.55 & 9.60 (2 bs, 1H). dried over 3 A molecular sieve) is added during 5 min to reach rt diluted with water (250 mL) The layers are separated the organic layer is washed twice with aq. citric acid (5%, 200 mL each) and twice with brine The combined organic layers are dried over MgSO4 concentrated in vacuo

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

Procedure: At −78° C. a solution of DIBAL in toluene (1.7M, 137 mmol) is added dropwise to a solution of (1R,3S,4S)-2-aza-bicyclo[2.2.1]heptane-2,3-dicarboxylic acid 2-tert-butyl ester 3-methyl ester (61.0 mmol) in THF (180 mL). After 80 min the solution is allowed to reach rt, stirred for additional 2 h and poured into a mixture of aq. NaOH solution (1.0M, 200 mL) and ice. EtOAc (150 mL) is added, the layers are separated and the aq. layer is extracted three times with EtOAc (150 mL each). The combined organic layers are washed with aq. NaOH solution (1.0M) and brine, dried over Na2SO4 and concentrated in vacuo to give a crude product which is used without further purification. LC-MS (basic): tR=0.78 min; [M+H]+=228.3. to reach rt the layers are separated the aq. layer is extracted three times with EtOAc (150 mL each) The combined organic layers are washed with aq. NaOH solution (1.0M) and brine dried over Na2SO4 concentrated in vacuo