Triethyl phosphonoacetate → tert-butyl (6R,7R)-7-(3,4-dichlorophenyl)-6-[(1E)-3-ethoxy-3-oxoprop-1-en-1-yl]-1,4-oxazepane-4-carboxylate

Participants

Reaction Steps

To a solution of lithium chloride (136 mg) and diazabicycloundecene (0.403 mL) in acetonitrile (26.7 mL) was added ethyl(diethoxyphosphoryl)acetate (0.642 mL), and the mixture was stirred at 20 min. tert-Butyl (6R,7R)-7-(3,4-dichlorophenyl)-6-formyl-1,4-oxazepane-4-carboxylate (1.00 g) was added and the mixture was stirred overnight. The reaction mixture was concentrated under reduced pressure, distilled water was added, and the mixture was extracted with ethyl acetate. The extract was washed with distilled water and brine, and dried over anhydrous sodium sulfate, and the solvent was evaporated under reduced pressure. The residue was purified by silica gel chromatography (hexane/ethyl acetate) to give the title compound (902 mg).

Provenance & Evidence