[C:1]([N:8]1[CH2:16][C:15]2[C:10](=[CH:11][CH:12]=[CH:13][CH:14]=2)[CH:9]1[C:17]([O:19][CH3:20])=[O:18])([O:3][C:4]([CH3:7])([CH3:6])[CH3:5])=[O:2].CI.[Li+].[CH3:24]C([N-]C(C)C)C>C1COCC1>[C:1]([N:8]1[CH2:16][C:15]2[C:10](=[CH:11][CH:12]=[CH:13][CH:14]=2)[C:9]1([CH3:24])[C:17]([O:19][CH3:20])=[O:18])([O:3][C:4]([CH3:7])([CH3:6])[CH3:5])=[O:2]To a solution N-BOC-1,3-dihydro-2H-isoindole-1-carboxylic acid, methyl ester (38 mmol) and MeI (10 mL, 160 mmol) in 150 mL of anhydrous THF at −30° C. was added LDA (Aldrich, 1.5 M in cyclohexane, 51 mL, 76.5 mmol). The reaction was allowed to warm up to rt over 4 hr. The reaction was cooled to −30° C., and was quenched with saturated aqueous solution of NH4Cl (50 mL). The resulting mixture was partitioned between EtOAc and brine, and the product was extracted with EtOAc (3×100 mL). The combined extracts were dried over anhydrous MgSO4 and concentrated in vacuo. The residue was purified by flash column chromatography on silica gel eluted with 10:1 to 5:1 hexane/ether to afford N-BOC-1,3-dihydro-1-methyl-2H-isoindole-1 -carboxylic acid, methyl ester.
Wird geladen…
