[C:1]([N:6]1[CH2:10][CH2:9][O:8][C:7]1=[O:11])(=[O:5])/[CH:2]=[CH:3]/[CH3:4].FC(F)(F)S(O)(=O)=O.[CH3:20][O:21][C:22]1[CH:27]=[CH:26][C:25]([NH2:28])=[CH:24][CH:23]=1.COC1C=CC(N)=CC=1.[Cl-].[NH4+]>O1CCCC1>[CH3:20][O:21][C:22]1[CH:27]=[CH:26][C:25]([NH:28][CH:3]([CH3:4])[CH2:2][C:1]([N:6]2[CH2:10][CH2:9][O:8][C:7]2=[O:11])=[O:5])=[CH:24][CH:23]=1
In a stream of nitrogen, a solution of 3-crotonoyl-1,3-oxazolidin-2-one (776 mg, 5.0 mmol), anisidine trifluoromethanesulfonate (1.64 g, 6.0 mmol), anisidine (3.1 mg, 0.005 mmol) and Pd((R)-segphos)(H2O)2(OTf)2 (26.3 mg, 0.005 mmol) in tetrahydrofuran (5 ml) was stirred at room temperatures for 24 hours. When no starting material remained was noticed, a saturated aqueous solution of ammonium chloride was added to quench the reaction and the resulting mixture was extracted with ethyl acetate. The organic layer was concentrated and purified by a silica gel column chromatography (hexane: ethyl acetate=1:1) to give the objective 3-[3-(4-methoxyphenylamino)butyryl]-1,3-oxazolidin-2-one (1.16 g, in a yield of 83%). The enantiomeric excess ratio was determined to be 97% e.e. by a liquid chromatography with an optical isomer separating column (column: AD-H).
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