Potassium Carbonate → (+/-)3-Cyanomethylene-1-azabicyclo[3.2.1]octane

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Reaction Steps

Diethyl cyanomethylphosphonate (5.67 g, 0.032 mole) in THF (75 ml) was added over 10 minutes to a stirred solution of potassium tert-butoxide (3.60 g, 0.032 mole) in THF (75 ml) at 0° C. The reaction mixture was then cooled to -20° C. before dropwise addition of 1-azabicyclo[3.2.11octan-3-one* (3.64 g, 0.029 mole) in THF (50 ml) over 15 minutes. The mixture was allowed to warm to room temperature, stirred for 1h, and then poured into 20% aqueous potassium carbonate (150 ml) and extracted with ethyl acetate (3×200 ml). The combined organic extracts were dried (Na2SO4) and evaporated to give the title compound (D11) as a 6:5 mixture of E and Z isomers (3.88 g, 90%). The isomers could be separated chromatographically on silica using 3% methanol/chloroform as eluant to give in order of elution the Z-isomer and the E-isomer as oils.

Provenance & Evidence