Tetrahydrofuran → HCID 59883201, compound

HRID 1635604Notes

Reaction equation

[NH2:1][C@H:2]([CH:17]1[CH2:22][CH2:21][CH2:20][CH2:19][CH2:18]1)[C:3]([C:11]1[CH:16]=[CH:15][CH:14]=[CH:13][CH:12]=1)([C:5]1[CH:10]=[CH:9][CH:8]=[CH:7][CH:6]=1)[OH:4].C[B:24]1[O:29]B(C)OB(C)O1.O1CCC[CH2:33]1>>[CH:17]1([C@@H:2]2[C:3]([C:11]3[CH:12]=[CH:13][CH:14]=[CH:15][CH:16]=3)([C:5]3[CH:10]=[CH:9][CH:8]=[CH:7][CH:6]=3)[O:4][B:24]([O:29][CH3:33])[NH:1]2)[CH2:22][CH2:21][CH2:20][CH2:19][CH2:18]1

Participants

Reactant 3

HCID 8028Tetrahydrofuran

HCID 574072Trimethylboroxine

HCID 12088879(R)-2-amino-2-cyclohexyl-1,1-diphenylethanol

Product 1

HCID 59883201HCID 59883201, compound

Procedure

(R)-2-amino-2-cyclohexyl-1,1-diphenylethanol (59 mg, 0.2 mmol), dry tetrahydrofuran (2 mL) and trimethylboroxine (27.2 μL, 0.24 mmol) were added to a dry flask under an atmosphere of nitrogen, then stirred for 1.5 hr to form a solution of (R)-4-cyclohexyl-5,5-diphenyl-2-methoxy-1,3,2-oxazaborolidine. Borane dimethylsulfide complex (100 μL, 1.0 mmol) was added and the reaction stirred for 30 minutes. Then, a solution of bromoacetophenone (199 mg, 1.0 mmol) in dry tetrahydrofuran (4 mL) was added at the rate of 9 mL/hr by means of a syringe pump. After 1.5 hr, methanol was added to quench the reaction and then, the solvent was removed by evaporation. The resulting residue was chromatographed on silica gel (hexane/ethyl acetate 20:1) and combination of the like fractions, followed by removal of the solvent gave (R)-2-bromo-1-phenylethanol (130 mg, 98.7% ee). The enantiomeric excess was measured by HPLC (Chiralcel OD-H column, mobile phase, hexane/2-propanol 9:1, flow rate=0.7 mL/min).

Sources & evidence

ORD record: ord-20c93e36e8de437dbbed35ce2777dc9c
Source dataset: uspto-grants-2003_01
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US06509472B2

Reaction notes

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