Transcript Silenes: Novel Synthesis of Reagents for Olefin

Investigating Diels-Alder reactions
Rachel E. Fairbairn, Alan. M. Kenwright, Jonathan D. Sellars*, Patrick G. Steel
Science Laboratories, University of Durham, South Road, Durham, DH1 3LE
[email protected], [email protected]
Introduction
The Diels–Alder reaction is an organic chemical reaction (specifically, a cycloaddition) between a conjugated diene and a
substituted alkene, commonly termed the dienophile, to form a substituted cyclohexene system.
 UV light was then used to polarise the product into a new
compound.
O
Diels-Alder and polarisation reaction
Diels-Alder
Polarisation
O
Methodology


The compounds used in this experiment were thymoquinone and 1,5-dimethylquinone (see above)
500 mg of starting material added to an excess of dry solvent (in this case dichloromethane). Dicyclopentane was then
distilled to make cyclopentane, and added in excess.
Mixture then cooled to 0°celcius and left for an hour.
Mixture heated back up and left for an hour to reflux
Product then evaporated to a pale yellow oil. A hydrogen NMR was then run to ensure that the product was the desired
one.
After creating the product, 500mg of it was dissolved in acetone and it was then run through a polarizer in order to
create a new compound through free radical substitution.
The product was then evaporated down again to a clear oil, and run through a hydrogen NMR to confirm the product.





Nomenclature
1
2
10
11
9
8
3
4
4
7
5
3
6
2
6
1
7
5
9
10
11
8
Conclusion
Found that many compounds were labelled incorrectly in terms of named compounds in IUPAC.
The carbon numbering changed on each compound, meaning there is no unified pattern.
References
Acknowledgements
 http://en.wikipedia.org/wiki/Diels%E2%80%93Alder_reaction
 http://en.wikipedia.org/wiki/Polarizer
 http://en.wikipedia.org/wiki/Free_radical_substitution
 http://en.wikipedia.org/wiki/Cycloaddition
Thanks to:
 Dr Jonathan Sellars
 Dr Alan Kenwright
 Dr Patrick Steel
 Durham University Organic Chemistry
department