Acetic Acid → 3,5-Dioxohexanoic acid

Participants

Reaction Steps

The resulting fully protected dipeptide ester was treated with 30% trifluoroacetic acid in dichloromethane at ambient temperature for 40 minutes, neutralized with saturated aqueous sodium bicarbonate solution, and extracted into ethyl acetate. Evaporation gave the partially deprotected dipeptide, which was redissolved in dry THF and added to a stirring solution of Na,Ne -dibenzyloxycarbonyl-L-lysine, N-methylmorpholine an isobutyl chloroformate in dry THF at -20° C. The formed, fully protected tripeptide ester was totally deprotected by treatment with hydrogen gas in glacial acetic acid at ambient temperature in the presence of 10% Pd-C catalyst. Filtration through a layer of Celite, lyophilization from water, and purification by liquid chromatography on a C-18 reverse-phase column gave the desired tripeptide ester as its triacetate salt.

Provenance & Evidence