Sciencemadness Discussion Board

Carbohydrate esters

hot84svo - 5-2-2005 at 07:22

Does anyone have experiance with manufacting of esters from Fructose?

Thanks in advance

JohnWW - 5-2-2005 at 10:24

I have heard of sucrose acetate being used as an adulterant in "methylated spirits" to render it unpalatable.

mick - 8-2-2005 at 13:50

This sounds like school work.
Depends on the ester required.
Do you want to selectively esterify the secondary or primary OHs.
I have not used fructose but with other sugars, acid chloride + amine under fairly dry conditions usually works. The xs acid chloride takes out the water. The sugar dissolves and when esterified and the amine HCl is precipitated, Dichoromethane seems to be a good solvent, hydrophobic so fairly dry to begin with (note I do not think you should try to dry DCM with alkali eg NaOH).

I think that works for acetates, benzoates and other stuff.

If you esterify the whole lot you can also selectivly de-esterify the different OHs.

Acid anhydrides should work.

The standard azeotropic distillation with the right catalyst should work as well, but slower and the yield might be lower

mick

sparkgap - 11-2-2005 at 10:39

Regarding the acid anhydrides, yes, that is a good way of acylating carbohydrates should you find the need to, if the anhydrides are readily accessible. Otherwise, have your SOCl2 or POCl3 handy. *shudder*

Selective acylation for carbohydrates is a bitch to try. You might want to be familiar with the numerous protecting groups available before attempting such. ;)

off-topic, but a colleague of mine is doing research on esterifying sucrose with medium-chain fatty acids. I might ask him a bit before posting more.

sparky (^_^)