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ChemicalBook CAS DataBase List Furaneol
3658-77-3

Furaneol synthesis

8synthesis methods
Furaneol can be prepared by cyclization of hexane-2,5-diol-3,4-dione in the presence of an acidic catalyst.The dione is the ozonization product of 2,5- hexynediol, which is obtained by ethynylation of acetaldehyde.
In another process, a dialkyl ??-methyldiglycolate (formed from an alkyl lactate and an alkyl monochloroacetate) is reacted with dialkyl oxalate in the presence of a sodium alkoxide and dimethylformamide. The reaction product is cyclized, alkylated, hydrolyzed, and decarboxylated.In another process, a dialkyl ??-methyldiglycolate (formed from an alkyl lactate and an alkyl monochloroacetate) is reacted with dialkyl oxalate in the presence of a sodium alkoxide and dimethylformamide. The reaction product is cyclized, alkylated, hydrolyzed, and decarboxylated .
-

Yield:3658-77-3 81.4%

Reaction Conditions:

with hydrogenchloride;sodium hydroxide in water;

Steps:

1 EXAMPLE 1

EXAMPLE 1 A solution of 48 g of sodium hydroxide and 37.2 g of ethyl 5-methyl-3,4-dihydroxy-2-furoate of 98.4% purity in 225 ml of water was allowed to stand at room temperature for 40 hours. The mixture was diluted with 200 g of water and 22.8 g of gaseous methyl bromide was added with stirring over a period of one hour at room temperature followed by an additional stirring period of two hours. The pH of the solution was adjusted to 5 by the addition of concentrated hydrochloric acid solution. Extraction with methyl t-butyl ether yielded 21.5 9 of 2,5-dimethyl-4-hydroxy-3[2H] furanone of 95.3% purity (molar yield 81.4%).

References:

US5412121,1995,A

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