# How to convert glucose to fructose

How to convert glucose to fructose? Moreover, can there be direct conversion(not necessarily in a single step), or we have to use indirect means, such as from sucrose, or other higher carbohydrates, and then separating fructose from the products?

• This conversion is done enzymatically on industrial scale using "glucose isomerase". – ssavec Dec 16 '13 at 16:11
• thank you! are there any other methods, more 'chemical' in nature? – Shubham Dec 16 '13 at 17:06
• Probably yes, but in general, all sugar chemistry is nasty, as the -OH groups are very similar and it is difficult to perform efficient synthesis. And impossible to do simple synthesis. – ssavec Dec 17 '13 at 6:52

## 2 Answers

After searching on Google about Isomerization of Glucose to Fructose, you can find so many sources that explain the process. I think that this one is easy to understand among them. It explains that

The isomerization of glucose to fructose is part of the glycolysis cycle that converts glucose to pyruvate. The way this is done is to isomerize the aldehyde (hemiacetal) glucose to the ketone (as a hemiacetal) fructose,and make another phosphate ester. The isomerization takes advantage of the ease of breakage of a C-H bond which involves a carbon next to a carbonyl carbon.

This gives a clear Idea on the mechanism of Glucose Isomerage to fructose. :)

Also see this.

Below by that process we can convert from glucose to fructose. At first a mixture of glucose and excess phenyl hydrazene is heated, so glucose will form osazone. Then if we will give $$\ce{Zn}$$ and acetic acid with this, fructose will form.