反应详情

Combine the product of Step 1 (1.50 g, 4.33 mmol) with (S)-methionine ethyl ester hydrochloride (0.92 g, 4.33 mmol), triethylamine (0.65 g, 6.5 mmol), hydroxybenzotriazole (HOBT) (0.66 g, 4.33 mmol), and 1-(3-dimethylaminopropyl)- 3-ethylcarbodiimide hydrochloride (DEC) (0.91 g, 4.8 mmol) in 25 ml dimethylformamide (DMF). Stir 18 h., partition between EtOAc-H20, wash with 1N NaHCO3 and concentrate. Chromatograph the resultant residue on silica, eluting with hexane-ether 1:1 to obtain an oil, [α]D26 =-17.4° (EtOH).

1. custompartition between EtOAc-H20
2. washwash with 1N NaHCO3
3. concentrationconcentrate
4. washChromatograph the resultant residue on silica, eluting with hexane-ether 1:1
5. customto obtain an oil, [α]D26 =-17.4° (EtOH)