Diisopropylamine → 4-Nitrobenzyl (5R,6S)-2-(cyclohepten-1-yl)-6-((1R)-1-hydroxyethyl)-1-carbapen-2-em-3-carboxylate

Participants

Reaction Steps

Under a nitrogen atmosphere, to a solution of 348 mg (1 mmol) of 4-nitrobenzyl (3R,5R,6S)-6-((1R)-1-hydroxyethyl) -2-oxo-1-carbapenam-3-carboxylate in THF (5 ml) was added 0.154 ml (1.1 mmol) of diisopropylamine at -78° C., and the mixture was stirred for 10 minutes. To the mixture was added 0.189 ml (1.08 mmol) of trifluoroacetic anhydride at the same temperature. After 15 minutes, to the mixture was added 5 ml of N-methylpyrrolidinone followed by 20.7 mg of tris(dibenzylideneacetone)dipalladium-chloroform, 42.5 mg (0.08 mmol) of tris(2,4,6-trimethoxyphenyl)phosphine, a solution of 389 mg (1.01 mmol) of cyclohepten-1-yl(tri-n-butyl)tin in N-methylpyrrolidinone (1 ml) and a solution of 225 mg (1.66 mmol) of N-methylpyrrolidinone (2 ml). The -78° C. bath was removed and the reaction mixture quickly raised to ambient temperature using a lukewarm water bath, and the mixture was stirred overnight at room temperature. The reaction mixture was poured into ethyl ether and the organic layer was washed with water followed by saturated aqueous sodium chloride. After the extract was dried over anhydrous magnesium sulfate, the solvent was removed. The residue was purified by silica gel column chromatography (elution with ethyl acetatehexane system) to give 148 mg (yield: 34.7%) of the title compound.

Provenance & Evidence