Methyl potassium malonate can be used in the total synthesis of (±)-vincorine, an akuammiline alkaloid which can find applications in biology. It can also be used to synthesize a key keto proline ester intermediate to prepare acutumine.
The general procedure for the synthesis of monomethyl malonate potassium salt from dimethyl malonate was as follows: referring to the literature method, dimethyl malonate (40.0 mmol), water (40.0 mmol), and ethanol (45 mL) were added to a 250 mL two-necked round-bottomed flask, and the mixture was stirred and mixed. The mixture was reacted in an oil bath at 40°C for 2 hours. Subsequently, a solution of potassium tert-butoxide (40.0 mmol) in ethanol (45 mL) was slowly added dropwise over 30 minutes. After the dropwise addition, the reaction was continued with stirring in a 40°C oil bath until the feedstock was completely consumed (the progress of the reaction was monitored by GC analysis). Upon completion of the reaction, the ethanol solvent was slowly evaporated using a rotary evaporator, followed by the addition of 20 mL of diethyl ether. The resulting solid product was collected by filtration and washed sequentially with a 1:1 mixture of ether and ethanol (5 mL × 2) and pure ether (10 mL × 3). The washed solid was transferred to a round-bottomed flask and dried under vacuum at 50 °C for 10 h. The final potassium salt of monomethyl malonate was obtained in 85% yield.
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