Cyanomethylenetributylphosphorane → Methyl 2-((3S,5R,6S)-5-(3-chlorophenyl)-6-(4-chlorophenyl)-1-((S)-1-(N-methylcyclopropanesulfonamido)butan-2-yl)-2-oxopiperidin-3-yl)propanoate

Participants

Reaction Conditions

Reaction Steps

A flask, containing a solution of methyl 2-((3S,5R,6S)-5-(3-chlorophenyl)-6-(4-chlorophenyl)-1-((S)-1-hydroxybutan-2-yl)-2-oxopiperidin-3-yl)propanoate (195 mg, 0.408 mmol; Example 127, Step E) and N-methylcyclopropanesulfonamide (165 mg, 1.223 mmol) in toluene (2038 μL) was evacuated and backfilled with Ar (5×). Then cyanomethylenetributylphosphorane (321 μL, 1.223 mmol) was added. The light brownish orange mixture was heated to 70° C. for 2 h. More N-methylcyclopropanesulfonamide (134 mg, 0.991 mmol) was added and the mixture was heated to 70° C. for 2 h. The mixture was heated to reflux overnight and then cooled to room temperature. The mixture was diluted with EtOAc and sat. aq. NaCl solution. The layers were separated. The organic layer was dried over Na2SO4 and concentrated under reduced pressure. The residue was purified by flash chromatography on silica gel (4 g column eluent: 0 to 100% EtOAc in hexanes) to give the title compound.

Provenance & Evidence