反应详情

Dissolve triphenylphosphine (41.97 g, 158.4 mmol) in fresh toluene (660 mL) and add bromine (8.14 mL, 158.4 mmol) until a yellow color persists. Add dropwise a solution of ditert-butyl(1S,2S,4S,5R,6R)-2-(tert-butoxycarbonylamino)-4-hydroxy-bicyclo[3.1.0]hexane-2,6-dicarboxylate (32.75 g, 79.2 mmol) in toluene (176 mL) and anhydrous pyridine (528 mL) during 45 min. Stir the reaction at 75° C. overnight. Cool to room temperature, dilute with ethyl acetate, filter and concentrate to dryness. Slurry the crude in methyl tert-butyl ether, filter to remove the solids and concentrate the filtrate to dryness. Purify the crude by silica gel chromatography (750 g) eluting with hexane:ethyl acetate (0:100 to 80:20) to obtain the title compound as a white solid (29.52 g, 78%). MS (m/z): 498, 500 (M+23).

1. customthe reaction at 75° C. overnight
2. filtrationfilter
3. concentrationconcentrate to dryness
4. filtrationfilter
5. customto remove the solids
6. concentrationconcentrate the filtrate to dryness
7. customPurify the crude by silica gel chromatography (750 g)
8. washeluting with hexane:ethyl acetate (0:100 to 80:20)