Iodomethyl pivalate → Pivaloyloxymethyl (1S,5R,6S)-2-(7-acetylimidazo[5,1-b]thiazol-2-yl)-6-((1R)-1-hydroxyethyl)-1-methyl-1-carbapen-2-em-3-carboxylate

Participants

Reaction Steps

To a solution of 38.1 mg of sodium (1S,5R,6S)-2-(7-acetylimidazo[5,1-b]thiazol-2-yl)-6-((1R)-1-hydroxyethyl)-1-methyl-1-carbapen-2-em-3-carboxylate in 3 ml of DMF was added 0.021 ml of pivaloyloxymethyl iodide under the atmosphere of argon at −30° C., and the mixture was stirred for 1.5 hours. The reaction mixture was diluted with 20 ml of ethyl acetate and washed with 20 ml of semi-saturated aqueous saline. The organic layer was dried over anhydrous magnesium sulfate, filtered, and concentrated under reduced pressure to a volume of 3 ml. The residue thus obtained was purified by column chromatography on silica gel (dichloromethane:methanol=20:1) and on Sephadex LH-20 (chloroform:methanol=1:1) in this sequence to give 35.8 mg of the title compound.

Provenance & Evidence