CID 406 → HCID 21321734, compound

Participants

Reaction Steps

A solution of 49.6 g (0.400 moles) dimethyl methylphosphonate (Aldrich) in 500 ml dry tetrahydrofuran was cooled to -78° in a dry nitrogen atmosphere. To the stirred phosphonate solution was added 188 ml of 2.34 M n-butyllithium in hexane solution (Alfa Inorganics, Inc. dropwise over a period of 40 minutes at such a rate that the reaction temperature never rose above -65°. After an additional 5 minutes stirring at -78°, 41.7 g (0.200 mole) methyl (1-adamantyl)-acetate was added dropwise at a rate that kept the reaction temperature less than -70° (20 minutes). After 1.0 hour at -78°, the reaction mixture was allowed to warm to ambient temperature, neutralized with 25 ml acetic acid and rotary evaporated to a white gel. The gelatinous material was taken up in 50 ml water, the aqueous phase extracted with 100 ml portions of methylene chloride (4x), the combined orgaic extracts were backwashed with water (4 × 100 ml), dried (MgSO4), and concentrated (water aspirator) to a crude residue and distilled, b.p 209°-212° (<0.02 mm) to give dimethyl 2-oxo-3-(1-adamantyl)propylphosphonate (2a ).

Provenance & Evidence