Methyl iodide → 8-Oxo-2,2,5,7-tetramethyl-3-oxa-1-azabicyclo[4.2.0]octane
Reaction equation
[CH:1](NC(C)C)(C)C.C([Li])CCC.[O:13]=[C:14]1[N:21]2[CH:16]([CH:17]([CH3:24])[CH2:18][O:19][C:20]2([CH3:23])[CH3:22])[CH2:15]1.CI>CCCCCC.C1COCC1.CCOC(C)=O.CN(C)P(N(C)C)(N(C)C)=O>[O:13]=[C:14]1[N:21]2[CH:16]([CH:17]([CH3:24])[CH2:18][O:19][C:20]2([CH3:23])[CH3:22])[CH:15]1[CH3:1]Participants
Reactant 4
Product 1
Reagents, catalysts & solvents 4
Conditions
- Temperature
- -78 °C
Procedure
THF, (20 ml) is placed under N2 treated with 1.54 ml diisopropylamine and cooled to -78° C. A solution of n-butyl lithium 1.97 M in hexane 5.6 ml is added dropwise over 5 min. The reaction mixture is stirred at -78° C. for 10 min and then treated with 8-oxo-2,2,5-trimethyl-3-oxa-1-azabicyclo[4.2.0]octane (1.55 g) in 15 ml THF added dropwise over 5 min. After another 10 min hexamethylphosphoramide 1.97 ml is added. The mixture is stirred another 10 min, then treated with 2 ml of methyl iodide. The reaction mixture is stirred at -78° for 154 min and allowed to warm to 25° C. and stirred for 15 min. The reaction mixture is diluted with EtOAc, washed once with pH 7 phosphate buffer and dried and evaporated. The residue is chromatographed on silica gel using 25% EtOAc/C 6 H6 as eluant to give 8-oxo-2,2,5,7-tetramethyl-3-oxa-1-azabicyclo[4.2.0]octane.
Workup
- additionadded dropwise over 5 min
- stirringThe mixture is stirred another 10 min
- stirringThe reaction mixture is stirred at -78° for 154 min
- temperatureto warm to 25° C.
- stirringstirred for 15 min
- washwashed once with pH 7 phosphate buffer
- customdried
- customevaporated
- customThe residue is chromatographed on silica gel using 25% EtOAc/C 6
Sources & evidence
- ORD record
- ord-cbcadffc95b14ccfbb0971f3d8680338
- Source dataset
- uspto-grants-1980_11
- Patent number
- US04232036
Reaction notes
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