Water → HCID 14819188, compound

Participants

Reaction Conditions

Reaction Steps

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.

Provenance & Evidence