Reaktion #64337

Reaktionsgleichung

sodium hydroxide

methyl 5-methyl-3,4-dihydroxy-2-furoate

ethyl 5-methyl-3,4-dihydroxy-2-furoate

hydrochloric acid

dimethyl sulphate

→

2,5-dimethyl-4-hydroxy-3[2H] furanone

Ausbeute 76.6%

Lösungsmittel

water

Reaktionsbedingungen

Aufarbeitung

1. 1
   ExtraktionExtraction with methyl t-butyl ether

Vorschrift

A solution of 32 g of sodium hydroxide and 33 g of a mixture containing 37.1% of methyl 5-methyl-3,4-dihydroxy-2-furoate and 52.1% of ethyl 5-methyl-3,4-dihydroxy-2-furoate in 320 ml of water was allowed to stand at room temperature for 20 hours. To the resulting mixture is added at 0° C. in one hour 25.2 g of dimethyl sulphate followed by an additional stirring period of three hours at 0° C. The pH of the solution was adjusted to 6.5 by the addition of concentrated hydrochloric acid solution. Extraction with methyl t-butyl ether yielded 18.1 g of 2,5-dimethyl-4-hydroxy-3[2H] furanone of 88.8% purity (molar yield 76.6%).

Quelle