Sodium hydride → HCID 117697992, compound

Participants

Reaction Conditions

Reaction Steps

To a solution of NaH (273 mg, 11.4 mmol) in tetrahydrofuran (30 mL) at 0° C. was added dropwise a solution of methyl 2-dimethoxyphosphorylacetate (2.1 g, 11.4 mmol) in tetrahydrofuran (10 mL). The reaction was stirred at 70° C. for 1 hour and then cooled to 0° C. again. To the reaction mixture was added a solution of benzyl 6-fluoro-7-oxo-3-oxa-9-azabicyclo[3.3.1]nonane-9-carboxylate 100c (1.7 g, 5.7 mmol) in tetrahydrofuran (8 mL). The reaction was allowed to warm up to room temperature and stirred 2 hours. After being quenched with 1 N HCl, the solvent was evaporated under reduced pressure. Ethyl acetate (20 mL) was added. The mixture was washed with water, brine, dried over Na2SO4 and evaporated to dryness. The crude mixture was purified on silica gel, eluted with 0 to 20% EtOAc in hexanes, to give the desired product benzyl (7Z/E)-6-fluoro-7-(2-methoxy-2-oxo-ethylidene)-3-oxa-9-azabicyclo[3.3.1]nonane-9-carboxylate 100d (1.8 g, 89%). MS: calc'd (MH+) 350, measured (MH+) 350.

Provenance & Evidence