Monobasic potassium phosphate → (6R,7R)-4-(tert-butoxycarbonyl)-7-(3,4-dichlorophenyl)-1,4-oxazepane-6-carboxylic acid

Participants

Reaction Steps

To a mixed solution of tert-butyl (6R,7R)-7-(3,4-dichlorophenyl)-6-formyl-1,4-oxazepane-4-carboxylate (7.3 g) in 2-methyl-2-butene (45 mL), tert-butanol (100 ml) and THF (100 ml) was added dropwise a solution of sodium chlorite (10.58 g) and potassium dihydrogenphosphate (16.38 g) in water (160 ml) under ice-cooling, and the mixture was stirred under ice-cooling for 2 hr. The reaction mixture was diluted with ethyl acetate. The diluted solution was washed with distilled water and brine, and dried over anhydrous magnesium sulfate. The solvent was evaporated under reduced pressure, and the residue was purified by silica gel chromatography (hexane/ethyl acetate) to give the title compound (7.0 g).

Provenance & Evidence