Diethyl isopropylidenemalonate → 2-(1-Cyclopropyl-1-methylethyl)malonic acid diethyl ester

Participants

Reaction Conditions

Reaction Steps

To a suspension of copper(I) iodide (7.61 g, 40.0 mmol) in THF (50 mL) at −50° C. was added cyclopropylmagnesium bromide (160 mL, 80.0 mmol, 0.5 M in THF) under nitrogen. After stirring for 15 minutes, the suspension was allowed to warm up and stirred at rt for 20 min before cooling back to −50° C. A solution of diethyl isopropylidenemalonate (4.0 g, 20.0 mmol) in THF (50 mL) was added, and the reaction was allowed to warm to rt over 3 h. The reaction mixture was then quenched with saturated sodium bicarbonate (200 mL), and filtered through Celite. The filtrate was extracted with ethyl acetate (3×250 mL). The combined extracts were dried over sodium sulfate and concentrated, and the resulting residue was purified by silica gel chromatography eluting with diethyl ether/hexanes (1:10) to afford 2-(1-cyclopropyl-1-methylethyl)malonic acid diethyl ester.

Provenance & Evidence