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Synlett 2005(2): 325-327  
DOI: 10.1055/s-2004-836066
LETTER
© Georg Thieme Verlag Stuttgart · New York

Radical Deoxygenation of 3-Azatricyclo[2.2.1.02,6]heptan-5-ols to 1,2-Dihydropyridines

David M. Hodgson*a, Matthew L. Jonesa, Christopher R. Maxwella, Osamu Ichiharab, Ian R. Matthewsc
a Department of Chemistry, University of Oxford, Chemistry Research Laboratory, Mansfield Road, Oxford OX1 3TA, UK
Fax: +44(1865)275708; e-Mail: david.hodgson@chem.ox.ac.uk;
b Evotec OAI, 151 Milton Park, Abingdon, Oxfordshire OX14 4SD, UK
c Syngenta, Jealott’s Hill International Research Centre, Berkshire RG42 6EY, UK
Further Information

Publication History

Received 1 October 2004
Publication Date:
10 December 2004 (online)

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Abstract

Radical deoxygenations of 7-alkyl-1-tosyl-3-azatricyclo[2.2.1.02,6]heptan-5-ols 9 (R = alkyl) give 7-alkyl-4-tosyl-2-aza­bicyclo[2.2.1]hept-5-enes 10, whereas 7-aryl-1-tosyl-3-azatricyclo[2.2.1.02,6]heptan-5-ols 9 (R = aryl) give 2-aryl-5-tosyl-1,2-dihydropyridines 12.

Key words

free radicals - deoxygenation - rearrangements - alcohols - dihydropyridines

    References

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    Typical Procedure for the Preparation of a 1,2-Dihydropyridine:
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7

CCDC 237474 available at http://www.ccdc.cam.ac.uk.

9

No 1,2-dihydropyridines 12 were observed as by-products from these reactions.

11

Variation of the thiocarbonyl moiety (thiocarbonyl-imidazole, or CSOPh) gave 1,2-dihydropyridine 12 (R =
4-MeOC6H4) in 43% and 59% yields, respectively.

13

Prepared in low yield (11%) by desulfonylation [6% Na-Hg, B(OH)3, MeOH] of 7-azanortricyclanol 9 (R = 4-MeOC6H4).