Triphenylphosphine → allyl (1S,5R,6S)-6-[1(R)-allyloxycarbonyloxy-ethyl]-1-methyl-2-(1-methyl-2,2-dioxo-8-triethylsilanyloxymethyl-1,2-dihydro-2-thia-1,3-diaza-cyclopenta[alpha]naphthalen-3-ylmethyl)-carbapen-2-em-3-carboxylate

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Reaction Steps

A solution of allyl (1S,5R,6S)-6-[1(R)-allyloxycarbonyloxy-ethyl]-2-hydroxymethyl-1-methyl-carbapen-2-em-3-carboxylate (365 mg, 1.0 mmol), triphenylphosphine (315 mg, 1.2 mmol), and 1-methyl-8-triethylsilanyloxymethyl-1,3-dihydro-2-thia-1,3-diaza-cyclopenta[α]naphthalene 2,2-dioxide (416 mg, 1.1 mmol) in anhydrous tetrahydrofuran (7 mL) is cooled in an ice-bath and stirred under a nitrogen atmosphere while diisopropyl azodicarboxylate (0.24 mL, 1.2 mmol) is added dropwise over a few minutes. The resulting solution is stirred in the cold for 30 minutes, then diluted with chloroform, washed with 5% aqueous sodium bicarbonate and brine, dried over sodium sulfate, filtered and evaporated under vacuum. The residue is purified by silica gel flash chromatography, eluting with hexane-ethyl acetate, to afford allyl (1S,5R,6S)-6-[1(R)-allyloxycarbonyloxy-ethyl]-1-methyl-2-(1-methyl-2,2-dioxo-8-triethylsilanyloxymethyl-1,2-dihydro-2-thia-1,3-diaza-cyclopenta[α]naphthalen-3-ylmethyl)-carbapen-2-em-3-carboxylate.

Provenance & Evidence