Hydrochloric Acid → HCID 56982543, compound

Participants

Reaction Conditions

Reaction Steps

To a solution of phosgene (2.5 ml) in toluene (15 ml) were added in turn triethylamine (1.45 ml) and a solution of (2S,4R)-1-allyloxycarbonyl-4-hydroxy-2-(2-methyl-3-oxo-1-butenyl)pyrrolidine (2.50 g) in toluene (10 ml) at 0° C. After stirring at 0° C. for 2 hours, the mixture was evaporated in vacuo and the residue was taken up into toluene (15 ml). Evaporation of the solvent gave a residue, which was dissolved in tetrahydrofuran (5 ml). This solution was added dropwise to a solution of dimethylamine (0.89 g) in a mixture of water (50 ml) and tetrahydrofuran (50 ml) under stirring at 0° C., and the stirring was continued for additional 10 minutes at 0° C. After adjusting pH to 7 with 1N hydrochloric acid, the mixture was diluted with ethyl acetate (200 ml). The organic layer was separated, washed with brine, dried over magnesium sulfate and evaporated. The residue was chromatographed on silica gel (100 ml) eluting with a mixture of n-hexane and ethyl acetate (6:4 V/V) to give (2S,4R)-1-allyloxycarbonyl-4-(dimethylcarbamoyloxy)-2-(2-methyl-3-oxo-1-butenyl)pyrrolidine (2.65 g).

Provenance & Evidence