(Trifluoromethyl)trimethylsilane → (4R)-1-((R)-1-(4-Methoxyphenyl)ethyl)-4-(2,2,2-trifluoro-1-hydroxyethyl)pyrrolidin-2-one
Reaction equation
[CH3:1][O:2][C:3]1[CH:8]=[CH:7][C:6]([C@H:9]([N:11]2[C:15](=[O:16])[CH2:14][C@@H:13]([CH:17]=[O:18])[CH2:12]2)[CH3:10])=[CH:5][CH:4]=1.[F-].C([N+](CCCC)(CCCC)CCCC)CCC.C[Si](C)(C)[C:39]([F:42])([F:41])[F:40]>C1(C)C=CC=CC=1>[CH3:1][O:2][C:3]1[CH:8]=[CH:7][C:6]([C@H:9]([N:11]2[CH2:12][C@H:13]([CH:17]([OH:18])[C:39]([F:42])([F:41])[F:40])[CH2:14][C:15]2=[O:16])[CH3:10])=[CH:5][CH:4]=1Participants
Reactant 3
Product 1
Reagents, catalysts & solvents 1
Conditions
- Temperature
- -60 °C
Procedure
Into a 250-mL 3-necked round-bottom flask purged and maintained with an inert atmosphere of nitrogen was placed a solution of (3R)-1-[(1R)-1-(4-methoxyphenyl)ethyl]-5-oxopyrrolidine-3-carbaldehyde 1.07 (7 g, 28.31 mmol, 1.00 equiv) in toluene (100 mL), trimethyl(trifluoromethyl)silane (2.9 mL), followed by the addition of tetrabutylammonium fluoride (1 mol/L in tetrahydrofuran) (1.53 mL) dropwise with stirring at −60° C. The resulting solution was stirred overnight at room temperature, quenched by the addition of 100 mL of water/ice and extracted with 3×300 mL of ethyl acetate. The organic layers were combined, washed with 3×300 mL of brine, dried over anhydrous sodium sulfate and concentrated under vacuum. The residue was applied onto a silica gel column eluting with dichloromethane: methanol (200:1-80:1) to afford (4R)-1-[(1R)-1-(4-methoxyphenyl)ethyl]-4-(2,2,2-trifluoro-1-hydroxyethyl)pyrrolidin-2-one. The diastereomers were separated by chiral HPLC (CHIRALPAK IC), and the later eluting diastereomer was collected to afford (R)-1-((R)-1-(4-methoxyphenyl)ethyl)-4-((S)-2,2,2-trifluoro-1-hydroxyethyl)pyrrolidin-2-one 1.29. This compound is the earlier diastereomer under RP-HPLC conditions (Gemini column, water/acetonitrile/TFA).
Workup
- customInto a 250-mL 3-necked round-bottom flask purged
- temperaturemaintained with an inert atmosphere of nitrogen
- stirringThe resulting solution was stirred overnight at room temperature
- customquenched by the addition of 100 mL of water/ice
- extractionextracted with 3×300 mL of ethyl acetate
- washwashed with 3×300 mL of brine
- dry with materialdried over anhydrous sodium sulfate
- concentrationconcentrated under vacuum
- washeluting with dichloromethane: methanol (200:1-80:1)
Sources & evidence
- ORD record
- ord-0c2d96567530479f834d56fec80b0033
- Source dataset
- uspto-grants-2016_06
- Patent number
- US09376441B2
Reaction notes
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