Pivalaldehyde → 1-(2,2-Dimethylpropyl)-5-oxoproline

Participants

Reaction Steps

L-glutamic acid (1.47 g, 10 mmol) was dissolved in 2N aqueous sodium hydroxide (10 ml, 20 mmol) and treated with a solution of trimethylacetaldehyde (1.09 ml, 10 mmol) in ethanol (5 ml) and then stirred at room temperature for 30 minutes. The mixture was cooled to 0° C. and treated with sodium borohydride (0.130 g). The mixture was allowed to warm to room temperature with stirring over 4 hrs and then acidified to neutral pH. Concentration in vacuo was followed by slurrying in ethanol and azeotroping three times with more ethanol. Finally the remaining material was suspended in ethanol (50 ml) and heated at reflux for 48 hrs. The mixture was then cooled to room temperature, salts were filtered off and the solvent was evaporated in vacuo to give a gum. Trituration with diethyl ether followed by drying afforded pure solid 1-(2,2-dimethylpropyl)-5-oxoproline (1.1 g).

Provenance & Evidence