Sodium 4-methyl-2-oxovalerate → N-(1-Carboxy-3-methylbutyl)-L-alanyl-L-isoleucine

Beteiligte Stoffe

Reaktionsschritte

A solution of L-alanyl-L-isoleucine (150 mg) and 4-methyl-2-oxopentanoic acid sodium salt (564 mg) in water was adjusted to pH 7 and treated with 140 mg of sodium cyanoborohydride at room temperature for several days. The reaction was quenched with strong acid ion-exchange resin, added to a column of the same resin, and eluted with 2% pyridine in water. Freeze drying afforded 200 mg (84.9%) of white fluffy solid, N-(1-carboxy-3-methylbutyl)-L-alanyl-L-isoleucine. Mass spectrum showed peaks at 460 for the disilylated derivative, and 445 for disilyl molecular ion minus methyl (460-15). The nmr spectrum showed a broad doublet centered at 0.95 ppm, complex absorption in the 1.2-1.8 ppm range, and a broad weak singlet at 3.7 ppm.

Herkunft & Nachweise