tert-Butyl Dimethylphosphonoacetate → 6-tert-Butoxycarbonylamino-3-(6-methoxy-pyridin-3-yl)-hex-2-enoic Acid tert-Butyl Ester

Participants

Reaction Steps

To a stirred solution of t-butyl dimethylphosphonoacetate (6.86 g, 30.6 mmol) in tetrahydrofuran (150 mL) at −78° C. under argon was added a solution of sodium bis(trimethylsilylamide) (30.6 mL of a 1.0 M solution). After 15 min., a solution of 1-3 (3.0 g, 10.2 mmol) in tetrahydrofuran (30 mL) was added, and the reaction was warmed to ambient temperature, then heated to 40° C. for 1 h. The reaction mixture was then cooled to ambient temperature, diluted with ethyl acetate and washed with saturated aqueous sodium hydrogen carbonate, then saturated aqueous sodium chloride, and dried over anhydrous magnesium sulfate. The reaction mixture was filtered and concentrated at reduced pressure to give an oil that was purified by flash column chromatography (silica gel, 15 to 25% ethyl acetate/hexanes) to give 1-4 and its 2 isomer.

Provenance & Evidence