反应详情

温度

70 °C

Dissolved in 50 ml of acetonitrile were 2.00 g of Nε -t-butoxycarbonyl-L-lysyl-L-proline t-butyl ester and 3.53 g of 2-bromo-4-pentyl-γ-butyrolactone. After a dropwise addition of 0.76 g of triethylamine, the resultant mixture was heated and stirred at 70° C. for 40 hours. The reaction mixture was poured into chilled water, followed by extraction with ethyl acetate. The extract was washed successively with water, a 2% aqueous solution of sodium hydrogencarbonate, and water. After drying the extract over anhydrous sodium sulfate, it was distilled under reduced pressure. The residue was isolated and purified by chromatography on a silica gel column (chloroform:ethyl acetate=10:1-5:1), thereby obtaining as a colorless syrupy substance 2.00 g of Nα -(2-oxo-5-pentyl-3-tetrahydrofuranyl)-Nε -t-butoxycarbonyl-L-lysyl-L-proline t-butyl ester [in the formula (I), R1 =--(CH2)4CH3, R2 =H, R3 =--(CH2)4NHCOO-t-Bu, R4 and R5 =--(CH2)3 --, R6 = t-Bu (Compound 27)]. Upon analysis of Compound 27 by high-performance liquid chromatography, it was found to be a mixture of 4 types of diastereomers.

1. additionThe reaction mixture was poured
2. extractionfollowed by extraction with ethyl acetate
3. washThe extract was washed successively with water
4. customAfter drying the
5. extractionextract over anhydrous sodium sulfate, it
6. distillationwas distilled under reduced pressure
7. customThe residue was isolated
8. custompurified by chromatography on a silica gel column (chloroform:ethyl acetate=10:1-5:1)