Tetrahydrofuran → Tetraethyl 3-oxopentane-1,1-bisphosphonate

Participants

Reaction Conditions

Reaction Steps

A solution of N-methoxy-N-methyl-3,3-bis(diethoxyphosphinyl)propionamide (1.00 g, 2.6 mmol) in THF (5 ml) was slowly added to a slurry of 80% sodium hydride (80 mg, 2.7 mmol) in THF (10 ml) at 0° C. Stirring was continued until all of the hydride was consumed (~20 minutes). The solution was cooled to -78° C. and ethylmagnesium bromide (1.0 ml of a 3.0M solution in diethyl ether, 3.0 mmol) was added. After the addition, the reaction mixture was warmed to 0° C. and stirred for one hour. The reaction was quenched by pouring slowly into a well-stirred ice-cold mixture of ethanol (40 ml) and concentrated HCl (5 ml). The solvents were removed in vacuo, the residue was taken up in brine (20 ml) and extracted with dichloromethane (4×20 ml). The combined extracts were dried (Na2SO4), concentrated in vacuo, and the resulting oil was purified by flash chromatography on silica gel eluting with 10% i-propanol in ethyl acetate to give the title compound (0.50 g, 54%) as a pale yellow oil.

Provenance & Evidence