subskune
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Ideas to make long-chain alditols
Hey there,
I want to make some very long-chain alditols (sugar alcohols). Basically polymers.
The problem is: I have no idea how to start. The 1,2 Dihydroxyethylene does not exist in its -ene form. The route of how polyvinylalcohol is made does
not work, since the double bond is locked between two substitutents.
Any ideas?
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Pumukli
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Aren't these sugar-like compounds made from formaldehyde polymerized with Ca(OH)2? Are those something different?
Anyway, formaldehyde polymerization works best with a moderately strong base, hence Ca(OH)2 is used afaik.
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Metacelsus
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I thought formaldehyde polymerization gave polyoxymethylene: https://en.wikipedia.org/wiki/Polyoxymethylene
Although the polyols do have the right empirical formula, I don't think they would be the major product under base-catalyzed polymerization.
Doing some more research, I see this might also take place if calcium is present: https://en.wikipedia.org/wiki/Formose_reaction
It could make some short oligomers but it would require a considerable amount of optimization to get long chains.
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Pumukli
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Yes, Metacelsus, you are right. Subskune explicitely wants "very long chain" polyols, this Butlerov reaction may not yield it, even after several days
of condensations. 
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subskune
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The wiki entry states that the resulting alcohols of the formose reaction are C2-6. I thought of something like 100+.
Onthe other hand formaldehyde is the monomer of the repeating group of this alditols. Maybe there is a fancy way of converting POM directly. Papers on
this topic are quite scarce.
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Metacelsus
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The issue with aldose chains longer than C5 is that they can cyclize, which stops them from growing longer.
I bet it would be possible to develop a specialized catalyst for making long chains, but it certainly wouldn't be easy.
What are you planning to use these for? There may be substitutes.
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TGSpecialist1
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https://en.wikipedia.org/wiki/Vinylene_carbonate
Bottom of the page.
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Metacelsus
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Good idea! That should definitely work.
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subskune
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Thank you a lot!!! Exactly what I was looking for
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TGSpecialist1
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Note that if you'll use organic peroxide as a polymerization catalyst then your final polymer will be terminated with aldehyde groups.
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