culturenout
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Alcohol to alkane - Phytane synthesis from Phytol - HI/P
Hi all,
I am trying to produce phytane from phytol which I have produced through saponification (base promoted ester hydrolysis) of chlorophyll.
This is how far I got:
HI and red phosphorous react as a strong reducing agent that will even reduce a primary alcohol like phytol. Even so, a primary alcohol is still a
terrible reactant and I might have to heat the reaction and/or even pressurize it to maximize yield. However, ideally I would like to avoid
pressurizing experimental vessels for fear of a huge mess. Obtaining reagents is not an issue, time and yield is.
I will hydrogente the product alkene from the HI/P reaction with a Pb catalyst to obtain my alkane, phytane.
I could not find a detailed experimental setup for this reaction or expected yield for a long-chain hydrocarbon online since information about using
HI/P to produce meth (hey, you do you) is swamping the search results.
Help anyone?
[Edited on 15-6-2019 by culturenout]
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TGSpecialist1
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Convert alcohol to halide then reduce with borohydride?
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Chemi Pharma
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You'd better tosylate the alcohol with tosyl chloride in pyridine and reduce later with borohydride or KOtBu in DMSO. The yields are better.
Reducion of halides with borohydride only works with decent yields for primary and secondary iodides, in DMSO media. For bromides and chlorides I'd
rather dehalogenate them with Zn and NH4Cl in THF with good yield.
Look at the papers attached.
Attachment: Dehalogenation with Zinc, NH4Cl and THF.pdf (60kB)
This file has been downloaded 336 times
Attachment: dehalogenation with sodium borohydride and DMSO.pdf (566kB)
This file has been downloaded 323 times
Attachment: Tosylates synthesis and elimination.doc (65kB)
This file has been downloaded 434 times
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TGSpecialist1
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It would form an allylic halide which would probably be easier to reduce.
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culturenout
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Thank you very much!
would a reduction of iodides with Super-Hydride solution (lithium triethylborohydride in tetrahydrofuran) result in decent yields?
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Chemi Pharma
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Quote: Originally posted by culturenout  |
Thank you very much!
would a reduction of iodides with Super-Hydride solution (lithium triethylborohydride in tetrahydrofuran) result in decent yields?
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I think you don't need to spend a so expensive reagent like Super-Hydride to dehalogenate alkyl iodides. If you read the paper I brought above about
dehalogenation with borohydrides in DMSO media you'll verify that sodium borohydride can do this work with good yields in the case of iodides. if you
want to work with bromides and chlorides I recommend the other way, using Zn and NH4Cl in THF.
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