Methanol → HCID 68825515, compound

Participants

Reaction Steps

To a cooled (0° C.) solution of diethylphosphonoacetic acid ethyl ester (4.4 mL, 24.2 mmol) in tetrahydrofuran (50 mL) under an atmosphere of nitrogen were added a solution of 28% sodium methoxide in methanol (4.6 mL, 26.4 mmol), and then a solution of 3,3-dimethyl-4-oxopiperidine-1-carboxylic acid t-butyl ester (5.0 g, 22.0 mmol) in tetrahydrofuran (10 mL) and stirred for 3 hours at room temperature. After the reaction was completed, the solvent was removed under a reduced pressure and water was added to the residue. The mixture was extracted with ether, washed with water and saturated brine, and dried over anhydrous sodium sulfate. After drying, the extract was filtered and the filtrate was concentrated under a reduced pressure. The residue was subjected to silica gel column chromatography (developing solvent, hexane:ethyl acetate=6:1) to obtain 1.8 g (yield 32.1%) of 4-methoxycarbonylmethylene-3,3-dimethylpiperidine-1-carbxylic acid t-butyl ester (A) and 3.3 g (yield 58.9%) of 4-methoxycarbonylmethyl-3,3-dimethyl-3,6-dihydro-2H-pyridine-1-carboxylic acid t-butyl ester (B). Each of their physical properties is shown below.

Provenance & Evidence