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a glucoside maybe?


YT2095

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I`ve done a little research into this already and have come up with nothing yet.

 

2 strong solutions of Sugar (sucrose C12H22O11) and sodium hydroxide (NaOH).

both liquids are quite "thin" (not very viscose), and yet when combined they react to make a very thick syrup like liquid.

eventualy it will crystalise into a clear solid that isn`t at all sweet.

 

what is this reaction?

 

and does it form a glucoside, as that`s about the closest I came to any sort of answer (one that left me with more questions).

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mmm, strange. Couldn't it be an isomerisation reaction ?? That's what I found in my books of biochemistry. But that doesn't explain the fact that it becomes a sirup. The sweetness depends of the sugar you form. So that is possible.

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the only isomer reaction I`m aware of for sugar is with HCl IIRC.

Organic chem is a new area for me, so I`m TRYING to start with simple compounds 1`st, I figured household sugar wouldn`t be a bad place to start :)

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just a thought, but could the hydroxide in the Naoh bonded with the central oxygen, that connect the two monosacharides into a full sucrose molecule. thus forming a polymer that would cause the viscosity and goopines?

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I`ve no idea, orgo is a new area to me, that`s why I`m asking :)

 

Trust me to pick something that`s not in any of my text books or on google as a 1`st "go it alone" experiment :(

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After it becomes thick does the whole solution crystalise or do you mean you get a crystal percipitate with water?

 

The sodium in the NaOH needs a counter ion.

I'm pretty sure that the NaOH will initially break the glycosidic bond giving Glucose + a Sodium fructose salt.

 

After that I'm not too sure. Maybe you'll get glucose sodium salts forming if the NaOH is strong enough to deprotonate the alcohol groups. You might get your observations from this depending on solubility, however this will also create a lot of water... Maybe these can hydrate highly? Check if you can dissolve your product with more water.

 

I don't like the idea of forming a polymer because -OH groups are so bad leaving, In the presence of a strong acid for sure, but not in a base and you'd have to loose them to make a polymer.

 

You do have aldehydes keytones and NaOH so maybe an adol condensation? But I don' t think that would happen with all the alcohol groups present.

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From what I can remember, the reaction between sucrose and sodium hydroxide should leave you with sodium sucrate which is basically a sugar salt (And since it's an ionic salt it probably wouldn't have that 'sweet' taste). I have heard that sucrates have a gelatin like property to them when mixed with water, so from your descriptions that sounds fairly likely.

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ok, most of that went totaly over my head :)

 

but it IS water soluble and will only crystalise after the water has been driven off by gentle heat evaporation.

 

I don`t think it`ll make a polymer either, it`s far too simple a reaction for that.

 

sodium fructose... I`ll have to look that up and learn some more about it, it`s still all quite new to me at the moment and i`m basicly still understanding alkanes and OLs and hetro/homolytic fussion reactions :)

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i would think that the NaOH would attack the glycosidic linkage.

 

the Na+ migrates toward the free RO- radical forming the salt with glucose, and the OH- migrates toward the C+ radical, recreating the monosaccharide, more likely fructose beacuse of the more negative hemiacetyl group in glucose.

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not being able to be metabolised doesn`t make it useless? Sorbitol can`t be either, but tons of it are sold daily.

 

as for sugar salts, it`s the 1`st I`ve ever heard of them, that`s why I was asking :)

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it cannot be metabolized and what good are sugar salts anyway?

 

Maybe it's not very usefull but I'm pretty sure it can be metabolised.

Wouldn't contact with HCl in the stomac convert it too table salt and glucose/fructose then allowing it be metabolised?

 

Also I don't think you'd get sodium sucrate, you would most likely get sodium fructate and sodium glucate (correct me if my nomenclature is wrong, really my worst area in chemistry). The linkage would would probably be broken.

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Bluenoise,

 

I was thinking it would break the linkage also, that H would be replaced by an Na ion.

I was trying to make an intermediary to ultimately obtain an alcohol like 1,2,3 propan-triol (glycerine) but by saponification of a Sugar instead of a fatty acid.

I got sidetracked (and thus curious about) by it`s syrup like result :)

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i wouldnt be so sure the Cl- anion is more active than an alkyl oxide radical.

 

Radical? It's an ion isn't it?

Anyways your right the Cl- isn't as active and that's why it would convert it back. The sugar salt can be thought of as the conjugate base of the sugar (which can thought of as an acid because of the alcohol groups).

This base isn't as strong a base as NaOH and that's what drives the reaction.

It's just another acid base reaction when you add HCl.

Glucose (barley acidic) and table salt (neutral) are far more stable then HCl (strong acidic) and a Sodium sugar salt (strong base).

The -OH has far more covalent covalent character and is a stronger bond than -ONa. Also NaCl is more ionic and a stonger bond than HCl.

 

Correct me if i'm wrong, nursing a serious hangover today.

 

No you don't necessarily want to nutralize the acid in your stomac, and I was in no way suggesting you should. However sometimes you do. Though I don't see why someone would want to take antacids that contain calories that you can't taste. :D

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Bluenoise' date='

 

I was thinking it would break the linkage also, that H would be replaced by an Na ion.

I was trying to make an intermediary to ultimately obtain an alcohol like 1,2,3 propan-triol (glycerine) but by saponification of a Sugar instead of a fatty acid.

I got sidetracked (and thus curious about) by it`s syrup like result :)[/quote']

 

You can't really do saponification on a sugar since it doesn't contain fatty acid side chains. Sucrose is already like glycerine in many ways. Olestera the fat substitute is just 6 fatty acids bonded to sucrose in the same manner as they would be to glycerine. It taste like fat but you can't metabolise it because it's too bulky.

If you were to saponify Olestera you'd be left with soap and sucrose!!! So in some sense you were starting with you're goal.

 

Hmmm you may have partially suceeded in taking it closer to glycerine. Sugars are really like alcohols. They just have an aldehyde or ketone group as well. Breaking the sucrose linkage is just like the first step. You could even take it closer to glycerine by reducing the aldehyde/keytone or somehow cleaving the carbon-carbon bonds. The reduction shouldn't be too hard, but modification of the carbon bonds of sugars is extreemly tough from what I've been told. The bodies processes are far better then anything we've come up with for the most part. You might be able to use an enzyme to do it. But that's costly as well as other things.

 

Try something like this out,

Hydrolyze the sucrose with an acid like HCl, then nutralize with NaOH. This is an equilibrium so you'll have sucrose, glucose, and fructose present afterwards.

(starting with Glucose would be far easier though.)

Then try using an NaBH4 reducing solution plus follow up to convert glucose to a 6 long alcohol like glycerine, fructose will also be converted to it's 5 long alcohol.

 

There is a chance that the NaBH4 solution may also hydrolyze the sucrose so using an acid to do so before hand might not be necessary.

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glycerine has 3 carbon...

 

I never said it didn't.

I said like glycerine because the only real difference would be the length. If it was 3 in lenght I would have said it was glycerine

 

i would be very careful about using acids and then NaBH4. in fact i wouldnt advise you to do so' date=' as the NaBH4 would explosively react with the acid.[/quote']

 

I would be very careful when doing any chemistry whatsoever, plus never just mix chemicals if you don't have a good idea what will happen.

 

Note that I stated to neutralize the solution so you wouldn't be mixxing NaBH4 with an acid anyways

 

Also I recently did a reduction with an NaBH4 reducing solution imediatley followed by adding HCl (which is a necessary step), and it definatley didn't explode on me.

Here is the proceedure if you like... http://sciborg.uwaterloo.ca/course_notes/chemistry/chem265l/pdfs/exp7_cyclohexanol-version2.pdf

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oh i noticed how you mentioned to neutralize the solution. if you were to neutralize it with NaOH, you still would have water involved, which would explosively react with the NaBH4.

 

"Also I recently did a reduction with an NaBH4 reducing solution imediatley followed by adding HCl (which is a necessary step), and it definatley didn't explode on me."

yes, i believe that would be because the NaBH4 oxidized before you added the acid...

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oh i noticed how you mentioned to neutralize the solution. if you were to neutralize it with NaOH' date=' you still would have water involved, which would explosively react with the NaBH4.

 

"Also I recently did a reduction with an NaBH4 reducing solution imediatley followed by adding HCl (which is a necessary step), and it definatley didn't explode on me."

yes, i believe that would be because the NaBH4 oxidized before you added the acid...[/quote']

 

The NaBH4 was in excess, however I was using small quantities.

 

You're right you would have to remove the water present for this reaction to work.

The risk of explosion from NaBH4 comes from the evolution of H2 I believe. As long as one doesn't add large amounts or too quickly it shouldn't be much concern.

Personally I'd be just as concerned with the toxic properies of sodium borohydrie.

Nevertheless starting from glucose is definatley the way to go.

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plus the great heat change. you end up boiling water im sure in addition to yielding H2, just a thought.

 

Yes the reaction is quite violent and in quantity can reach the flash point of H2. NaBH4 is fairly flamible itself as well.

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