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Chemistry Forums for Students => Organic Chemistry Forum => Topic started by: lloydy on April 28, 2005, 03:13:30 PM

Title: Removing the Oxygen from Sugars
Post by: lloydy on April 28, 2005, 03:13:30 PM
Is there a way of removing the 02 from the sugar Glucose C6H1206? I would really aprecitate if you answered as this would be useful for my science project.

Lloydy
Title: Re:Removing the Oxygen from Sugars
Post by: Donaldson Tan on April 28, 2005, 07:00:36 PM
this seems like a tricky problem. attached is the structure of glucose. it's possible to substitute the -OH with something else but the oxygen in the ring is the one that is really headache. removing that oxygen involves breaking down glucose completely.
Title: Re:Removing the Oxygen from Sugars
Post by: GCT on April 30, 2005, 04:58:00 PM
I would suggest that you first observe the structure of glucose.  Are you asking to somehow produce oxygen gas through a reaction where glucose is one of the reactants?
Title: Re:Removing the Oxygen from Sugars
Post by: Mitch on April 30, 2005, 06:38:45 PM
Write a chemical equation.  :D
Title: Re:Removing the Oxygen from Sugars
Post by: jdurg on April 30, 2005, 11:32:10 PM
this seems like a tricky problem. attached is the structure of glucose. it's possible to substitute the -OH with something else but the oxygen in the ring is the one that is really headache. removing that oxygen involves breaking down glucose completely.

Yeah, that's actually quite easy.  Replace the -OH with -Cl and you have the latest craze known as 'Splenda'.   :biggrin2:
Title: Re:Removing the Oxygen from Sugars
Post by: lloydy on May 01, 2005, 11:44:13 AM
what im really after is

Glucose + "something" = a carbohyrdate +oxygen

or something along those lines
Title: Re:Removing the Oxygen from Sugars
Post by: constant thinker on May 04, 2005, 08:56:16 PM
Sugars are carbohydrates right? Just simple ones. Research enzymes that our bodies use to break down sugar or try the chlorine trick.
Title: Re:Removing the Oxygen from Sugars
Post by: Garneck on May 05, 2005, 02:03:48 AM
I think he ment "hydrocarbons"  ::)
Title: Re:Removing the Oxygen from Sugars
Post by: miaskows on May 20, 2005, 02:08:59 PM
Reaction that you actually have to carry out if you would like to remove O from sugars , it is Hydrogenolysis of their -OH and -COH groups  ( Hydro-de-Hydroxylation).
For example :
C6H12O6 + 7H2 (catalist)=C6H14 + 6H2O
Glucose is aldehydo alcohol and the hydroxyl groups (and aldehydo ones  that reduced  via -OH) of most primary and secondary alcohols  can seldom be cleaved by catalitic hydrogenation, but they can be reduced indirectly by conversion to a sulfonate and reduction of that compound with LiAlH4 as follows:
1)RCH2OH + SO3-Pyridine  = RCH2O-Sulfonate
2)RCH2O-Sulfonate + LiAlH4= RCH3 + ...
The two reactions can be carried out without isolation of the sulfonate if the alcohol is treated with pyridine-SO3 in Tetra Hydro Furane and then LiAlH4 added.

There are another methods for reducing of alcohols (and sugars), for example so called Barton-McCombie reaction:
1)Converting of sugar to carbonate derivative:
RCH2OH + COCl2 = RCH2-O-CO-O-(RCH2) + HCl+ ...
2) Reducing of the carbonate with appropriated radicals producing compound (as AIBN)
RCH2-O-CO-O- + AIBN= RCH3 +...



Title: Re:Removing the Oxygen from Sugars
Post by: miaskows on May 21, 2005, 07:00:48 AM
If you still insist on producing of  carbohydrates from sugars along with O2 as by product ,you can try electrolisis (reducing by electrolisis, has been described in the literature) as follows:
(simplest case-alphaGlucose)
C5(OH)5COH  (e) = C6(OH)nHm+ xO2
By carefully choosing of conditions(solvent, curient of electricity,concentration etc) you can obtain all of possible  products of reducing.
Title: Re:Removing the Oxygen from Sugars
Post by: xiankai on May 21, 2005, 08:01:35 AM
it sounds like the breaking of glucose into carbohydrases, where oxygen is then circulated bloodstream.

maybe u guys could put it into layman terms? im having a headache :X
Title: Re:Removing the Oxygen from Sugars
Post by: miaskows on May 23, 2005, 02:18:39 PM
I am still with that glucose "stripping off oxygen atoms" topic. Actually it is sounds as somthing great: solving of world's petroleum shortage by obtaining of  hydrocarbons (like hexane C6H14, component of  fuels) from cheap renewable natural search (sugars by hydrolysis of wood cellulose etc).
The topic itself may be considered as worth it's own serious forum.
Then there is one another method for reducing of glucose:
CH2OH-(CH-OH)4-COH + HI (heating)=
CH3-CHI-(CH2)3-CH3 +H2O+I2

CH3-CHI-(CH2)3-CH3 +H2 (catalist)=
CH3-(CH2)4-CH3 +HI
(I2 and HI could be easily recuperated)

<The mentioned above methods needs to be cross checked (the equations has been taken from the book of Org.Chem., but there could be mistakes everywhere now days, you know...)>
Title: Re:Removing the Oxygen from Sugars
Post by: lloydy on May 31, 2005, 12:04:18 PM
I am still with that glucose "stripping off oxygen atoms" topic. Actually it is sounds as somthing great: solving of world's petroleum shortage by obtaining of  hydrocarbons (like hexane C6H14, component of  fuels) from cheap renewable natural search (sugars by hydrolysis of wood cellulose etc).

Yup, this is what i am in essence trying to do. Have u anyidea on a catalyst for this reaction?
Title: Re:Removing the Oxygen from Sugars
Post by: xiankai on June 01, 2005, 12:47:40 AM
he did write down hydrogen as a catalyst..
Title: Re:Removing the Oxygen from Sugars
Post by: miaskows on June 01, 2005, 12:43:00 PM
Between common used catalysts of hydrogenation are Raney nickel, palladium-on-carcoal, platinum metal or its oxide and others.
Title: Re: Removing the Oxygen from Sugars
Post by: Jiro on April 11, 2006, 04:56:06 PM
LiAlH4?