Benzyl chloroformate → diphenylmethyl (S)-3-[(2S,3R,4R,5S)-5-(N-benzyloxycarbonyl-L-leucyl)amino-2,3,4,6-tetrahydroxyhexanoyl]amino-3-phenylpropionate

Participants

Reaction Steps

To a solution of (S)-3-[(2S,3R,4R,5S)-2,3,4,6-tetrahydroxy-5-(L-leucyl)aminohexanoyl]amino-3-phenylpropionic acid hydrochloride (4.35 g) in methanol (100 ml) was added a solution of diphenyldiazomethane (3.40 g) in methanol (100 ml) under ice-cooling and the mixture was stirred at room temperature for 15 hours. Removal of the organic solvent gave a residue, which was suspended in water (200 ml). To the suspension were added sodium hydrogencarbonate (2.20 g) and benzyl chloroformate (18 ml) and the mixture was stirred at room temperature for 2 hours. The reaction mixture was extracted with ethyl acetate and the extract was washed with saturated brine. The organic layer was dried over anhydrous sodium sulfate and concentrated under reduced pressure. The residue was recrystallized from ethyl acetate to give the title compound (5.95 g).

Provenance & Evidence