Propargyl chloroformate → HCID 10393852, compound

Participants

Reaction Conditions

Reaction Steps

To (1S,4aS,5S,8aR)-2,8a-dihydroxy-3,8-dimethyl-5-(1-methylethyl)-1,2,4a,5,6,7,8,8a-octahydronaphthalen-1-yl (2S,3aR,9bR)-6-chloro-9b-hydroxy-5-methyl-1,2,3,3a,5,9b-hexahydropyrrolo[2,3-c][2,1]benzoxazine-2-carboxylate (Preparation 144, 500 mg, 0.96 mmol) and 4-dimethylaminopyridine (350 mg, 2.9 mmol) in dichloromethane (25 ml) at 0° C. under nitrogen was added propargyl chloroformate (170 mg, 1.44 mmol) and the resulting mixture stirred at 0° C. for 30 minutes and at room temperature for 3 hours. The reaction mixture was diluted with dichloromethane (100 ml) and washed with citric acid solution (3×50 ml) and water (2×50 ml), dried (MgSO4) and concentrated in vacuo to give a solid. The crude product was purified by flash chromatography on silica (40 g) eluting with hexane:ethyl acetate (3:2). The pure fractions were combined and concentrated in vacuo to give the title product (462 mg, 80%).

Provenance & Evidence