Cobalt-Catalyzed Generation of 1,4-Dienes as Synthons for 1,3-Dicarbonyl Compounds and Their Application in Natural Product Syntheses

Abstract

The cobalt-catalyzed 1,4-hydrovinylation of alkenes with 1,3-dienes and the cobalt-catalyzed Diels-Alder reaction of alkynes with 1,3-dienes lead to acyclic and cyclic 1,4-dienes, respectively. These products can be transformed into 1,3-dicarbonyl functional groups by ozonolysis or alternative carbon-carbon double bond cleaving reactions. The application towards the synthesis of hepialone and a pyranone-type lipid from Vanilla beans is described.

Key words

cobalt - cycloaddition - 1,3-dicarbonyl compounds - ­Diels-Alder - hydrovinylation - ozonolysis

References

• 1a Leading reference: Chem. Rev.  1997,  97:  2463-2706  ; this special issue gives a comprehensive introduction into biochemical and biological aspects of polyketides
• 1b See also: Sattely ES. Fischbach MA. Walsh CT. Nat. Prod. Rep.  2008,  25:  757 
• 2 For a comprehensive review, see: Hilt G. Weske DF. Chem. Soc. Rev.  2009,  38:  3082 
• 3 Birch AJ. J. Chem. Soc.  1944,  430 
• 4 Tung JC. Chen MW. Noll BC. Taylor RE. Fields SC. Dent WH. Green FR. Synthesis  2007,  2388 
• 5a Hilt G. Janikowski J. Hess W. Angew. Chem. Int. Ed.  2006,  45:  5206 
• 5b Hilt G. Janikowski J. Org. Lett.  2009,  11:  774 
• 6a Hilt G. du Mesnil F.-X. Lüers S. Angew. Chem. Int. Ed.  2001,  40:  387 
• 6b Hilt G. Lüers S. Synthesis  2002,  609 
• 6c Hilt G. Lüers S. Schmidt F. Synthesis  2003,  634 
• 8a For 7a, see: Axenrod T. Mangiaracina P. Watnick CM. Wieder MJ. Bulusu S. Org. Magn. Reson.  1980,  13:  197 
• 8b For 7b, see: Alberola A. Andres C. Gonzalez Ortega A. Pedrosa R. J. Heterocycl. Chem.  1984,  21:  1575 
• 9a Rao BV. Rao AS. Synth. Commun.  1995,  25:  1531 
• 9b Kubo I. Matsumoto T. Wagner DL. Tetrahedron Lett.  1985,  26:  563 
• 10a MacDonald FK. Burnell DJ. J. Org. Chem.  2009,  74:  6973 
• 10b Wang H. Shuhler BJ. Xian M. J. Org. Chem.  2007,  72:  4280 
• 10c Zhang J. Li Y. Wang W. She X. Pan X. J. Org. Chem.  2006,  71:  2918 
• 10d Calad SA. Ćiraković J. Woerpel KA. J. Org. Chem.  2006,  72:  1027 
• 10e Jin M. Taylor RE. Org. Lett.  2005,  7:  1303 
• 11 Ramaroson-Raonizafinimanana B. Gaydou EM. Bombarda I. J. Agric. Food Chem.  1999,  47:  3202 
• 12 For the generation of oxygen-free ozone, see experimental section and: Schutt WS. Sigman ME. Li Y. Anal. Chim. Acta  1996,  319:  369 

7

Ligands such as 2,4,6-trimethyl-N-(pyridin-2-ylmethyl-ene)aniline (as a representative of a pyridine-imine-type ligand) as well as N,N"-dibutylethane-1,2-diimine or N,N"-dicyclohexylethane-1,2-diimine (diimine-type ligands) can be applied.