Dimethylformamide → (1R,5S,6S)-2-[(4R)-pyrrolidine-2-thion-4-ylthio]-6-[(1R)-1-hydroxyethyl]-1-methylcarbapen-2-em-3-carboxylic acid isobutyryloxymethyl ester

Participants

Reaction Steps

To a mixture of (1R, 5S, 6S)-2-[(4R)-pyrrolidine-2- thion-4-ylthio]-6-[(1R)-1-hydroxyethyl]-1-methylcarbapen-2- em-3-carboxylic acid potassium salt (0.34 g), N,N-dimethylformamide (3 ml) and potassium carbonate (0.12 g) is added dropwise isobutyryloxymethyl iodide (0.27 g) under ice cooling. After stirring the mixture at the same temperature for 30 minutes, ethyl acetate (10 ml) is added to the reaction mixture, and the mixture is washed with water, and the organic layer is dried and evaporated under reduced pressure to remove the solvent. The residue is purified by silica gel flash column chromatography (eluent, chloroform: ethanol=20:1), followed by crystallization from isopropyl ether and ethyl acetate to give (1R, 5S, 6S)-2-[(4R)-pyrrolidine-2-thion-4-ylthio]-6-[(1R)-1-hydroxyethyl]-1-methylcarbapen-2-em-3-carboxylic acid isobutyryloxymethyl ester (0.12 g) as colorless needles.

Provenance & Evidence