Diethyl methylmalonate → HCID 53764332, Verbindung

Reaktionsgleichung

[Na].[CH3:2][CH:3]([C:9]([O:11][CH2:12][CH3:13])=[O:10])[C:4]([O:6][CH2:7][CH3:8])=[O:5].Br[C@@H:15]1[CH2:19][CH2:18][CH2:17][C@H:16]1Br>C(O)C>[CH2:12]([O:11][C:9](=[O:10])[C:3]([CH:19]1[CH2:18][CH2:17][CH:16]=[CH:15]1)([CH3:2])[C:4]([O:6][CH2:7][CH3:8])=[O:5])[CH3:13]

Komponenten

Versuchsvorschrift

52.4 g of sodium, cut into small pieces, was introduced into a three-necked flask equipped with dropping funnel, reflux condenser, and KPG agitator. Under an argon atmosphere, 790 ml of absolute ethanol was added dropwise thereto within 3 hours so that the reaction mixture was boiling vigorously. Within 1.5 hours, 157 g of diethyl methylmalonate was added dropwise to the hot, slightly turbid alcoholate solution. The mixture was agitated for another hour and then 205 g of trans-1,2-dibromocyclopentane was added dropwise within one hour to the cooled-off solution. Thereafter the solution was refluxed for 17 hours. After concentration of the reaction solution on a forced circulation evaporator, the residue was combined with ether and dilute hydrochloric acid, the organic phase was washed neutral with saturated sodium chloride solution, dried over sodium sulfate, and distilled under vacuum, thus obtaining 170 g, bp1.5 90°-105° C.