Dimethyl Sulfoxide → HCID 68008509, compound

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Reaction Steps

To a solution of oxalyl chloride (0.092 ml, 1.05 mmol) in dichloromethane (1.75 ml) at −78° C. was added dropwise DMSO (0.149 ml, 2.10 mmol). The reaction mixture was stirred for 10 min and then a solution of (2S,6S,12S,13aS,14aR,16aS)-ethyl 2-(benzoyloxy)-6-(tert-butoxycarbonylamino)-12-hydroxy-5,16-dioxooctadecahydrocyclopropa[e]pyrrolo[1,2-a][1,4]diazacyclopentadecine-14a-carboxylate (Example 1b, 0.43 g, 0.698 mmol) in dichloromethane (4 ml) was added dropwise. The reaction mixture was stirred at −78° C. for 30 min and triethylamine (0.730 ml, 5.24 mmol) was added dropwise. The reaction mixture was stirred at −78° C. for 15 min and warmed to room temperature and stirred for 1.5 hr. The reaction mixture was quenched with water, stirred for 30 min and extracted with dichloromethane and the organic layer dried over anhydrous sodium sulfate, filtered, and evaporated under reduced pressure. The residue was purified by flash chromatography on silica gel (dichloromethane/methanol=40/1) to provide the title compound (2S,6S,13aS,14aR,16aS)-ethyl 2-(benzoyloxy)-6-(tert-butoxycarbonylamino)-5,12,16-trioxooctadecahydrocyclopropa[e]pyrrolo[1,2-a][1,4]diazacyclopentadecine-14a-carboxylate (0.36 g, 0.59 mmol, 84% yield).

Provenance & Evidence