Question

Suggest a possible mechanism for the acid catalyzed reaction of a typical ketohexose to give 5-hydroxymethylfurfural.

Answer 1

Answer:

See explanation

Explanation:

Taking the acid catalysed hydrolysis of fructose C6H12O6, the mechanism begins with the protonation of an -OH group as shown.

This is now followed by dehydration and formation of a keto-enol tautomer. The keto form is now dehydrated followed by the protonation of a second -OH group.

A second dehydration followed by deprotonation leads to the formation of  5-hydroxymethylfurfural.

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