(2S,5R)-6-(Benzyloxy)-7-oxo-1,6-diazabicyclo[3.2.1]octane-2-carboxylic acid → (2S,5R)-methyl 6-(benzyloxy)-7-oxo-1,6-diazabicyclo[3.2.1]octane-2-carboxylate
Reaction equation
[CH2:1]([O:8][N:9]1[C:15](=[O:16])[N:14]2[CH2:17][C@H:10]1[CH2:11][CH2:12][C@H:13]2[C:18]([OH:20])=[O:19])[C:2]1[CH:7]=[CH:6][CH:5]=[CH:4][CH:3]=1.[CH3:21][Si](C=[N+]=[N-])(C)C.CCCCCC>C1(C)C=CC=CC=1.CO>[CH2:1]([O:8][N:9]1[C:15](=[O:16])[N:14]2[CH2:17][C@H:10]1[CH2:11][CH2:12][C@H:13]2[C:18]([O:20][CH3:21])=[O:19])[C:2]1[CH:7]=[CH:6][CH:5]=[CH:4][CH:3]=1Participants
Reactant 2
Product 1
Reagents, catalysts & solvents 2
Procedure
66 mg (0.239 mmol) of (2S,5R)-6-(benzyloxy)-7-oxo-1,6-diazabicyclo[3.2.1]octane-2-carboxylic acid was dissolved in toluene (0.6 mL) and methanol (0.6 mL), and, under ice cooling, 0.54 mL (0.324 mmol) of 0.6 M trimethylsilyldiazomethane-hexane solution was added, followed by stifling for 20 minutes. The reaction solution was concentrated under reduced pressure, and the resulting residue was subjected to silica gel column chromatography (hexane/ethyl acetate=2/1) to afford 21.5 mg of the title compound as a colorless solid (yield 31%). The resulting solid was recrystallized with ethyl acetate-hexane, the generated precipitate was filtered off, the wet crystal was washed with hexane, and subsequently dried under reduced pressure at room temperature to afford the title compound as a colorless crystalline powder. Enantiomeric excess: 99.9% ee or more (CHIRALPAK AD-H, 4.6×150 mm, hexane/ethanol=2/1, UV 210 nm, flow rate 1 mL/min., retention time 12.8 min.).
Workup
- concentrationThe reaction solution was concentrated under reduced pressure
Sources & evidence
- ORD record
- ord-c63151890e17440d97a6bfd234dfe5f4
- Source dataset
- uspto-grants-2016_03
- Patent number
- US09284273B2
Reaction notes
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