Dimethyl Sulfoxide → 3-[(N-acetylprolyl)alanylprolylamino]-2,2-dihydroxybutanoic acid, methyl ester

Participants

Reaction Steps

To a stirred solution of oxalyl chloride (0.12 ml, 1.43 mmol) in methylene chloride (1.5 ml) under an argon atmosphere and cooled in a dry ice-acetone bath was added dropwise a solution of dimethylsulfoxide (0.20 ml, 2.86 mmol) in methylene chloride (1.5 ml). After 5 minutes, a solution of the product of example 59 (0.32 g, 0.72 mmol) in methylene chloride (1.5 ml) was added and the reaction mixture stirred for 25 minutes. Triethylamine (0.50 ml, 3.58 mmol) was added and the reaction mixture warmed to room temperature. The reaction mixture was placed directly onto a silica gel column and eluted with methylene chloride-methanol. Evaporation of the appropriate fractions on a rotary evaporator, addition of water (3 ml) to the residue and evaporation gave the above-namedproduct.

Provenance & Evidence