Formaldehyde → 2-Acetyl-3,8-dimethyl-8-azabicyclo[3.2.1]oct-2-ene

Participants

Reaction Steps

To a stirred mixture of 2-acetyl-3-methyl-8-azabicyclo[3.2.1]oct-2-ene (1.2083 g, 0.0073 mol) and aqueous formaldehyde (2.7 ml, 0.036 mol, 37 percent) in 15 ml acetonitrile was added sodium cyanoborohydride (0.7352 g, 0.0117 mol). After stirring for 15 minutes, the reaction was made acidic by addition of 15 ml glacial acetic acid over a 45 minute period. The solution was made basic by the addition of an aqueous solution of ammonium hydroxide. The basic solution was extracted 3 times with ethyl acetate, the organic layer was then dried using sodium sulfate and concentrated under reduced pressure. The concentrated residue was purified by silica gel column chromatography (using 9 parts diethyl ether and 1 part triethylamine) followed by bulb-to-bulb distillation (80° C. (0.4 mmHg)) to give 2-acetyl-3,8-dimethyl-8-azabicyclo[3.2.1]oct-2-ene as a brownish liquid.

Provenance & Evidence