carlituz
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Cyclopentadiene by cyclopentenone
Hi everybody,
May anybody help me to plan a synthesis of cyclopentadiene starting from cyclopentenone? I was thinking to the following:
- Reduction of cyclopentenone to cyclopentenol by enzymes
- Dehydration of cyclopentenol to cyclopentadiene by strong acid
Do you think this path may be feasible? Can anyone suggest any amelioration to it, or maybe something different (e.g. without passage through the
alcohol)?
Thank you
Carlo
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Boffis
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No, assuming you can reduce the ketone to an alkohol, dehydration of this will only give cyclopentene ie only one ethylenic double bound. But if you
add say bromine to this to obtain 1,2 dibromocyclopentane it may then be possible to de-hydrohalogenate this compound to cyclopentadiene but it may
also give a single acetylenic triple bound instead. I think you need to do some more reading.
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UC235
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Dehydrohalogenation of the dibromocyclopentane will definitely not give an alkyne due to ring strain. However I suspect it will mostly give
1-bromocyclopentene which will be unreactive to base.
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CuReUS
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Quote: Originally posted by Boffis  | | No, assuming you can reduce the ketone to an alkohol, dehydration of this will only give cyclopentene ie only one ethylenic double bound.
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He is using cyclopentenenone,not cyclopentanone .So on dehydration,cyclopentadiene will form
| Quote: Originally posted by carlituz |
May anybody help me to plan a synthesis of cyclopentadiene starting from cyclopentenone? I was thinking to the following:
- Reduction of cyclopentenone to cyclopentenol by enzymes
- Dehydration of cyclopentenol to cyclopentadiene by strong acid
Do you think this path may be feasible? |
yes ,it will work
| Quote: | | Can anyone suggest any amelioration to it, or maybe something different (e.g. without passage through the alcohol)? |
go to pg 15 of pdf(pg 410 of original article) - 2,4 -pentanediol and p-toulenesulphonic acid
http://www.arkat-usa.org/get-file/48168/
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