Synfacts 2008(8): 0783-0783  
DOI: 10.1055/s-2008-1077896
Synthesis of Natural Products and Potential Drugs
© Georg Thieme Verlag Stuttgart ˙ New York

Synthesis of (-)-β-Caryophyllene

Contributor(s):Philip Kocienski, Arndt W. Schmidt
O. V. Larionov, E. J. Corey*
Harvard University, Cambridge, USA
An Unconventional Approach to the Enantioselective Synthesis of Caryophylloids
J. Am. Chem. Soc.  2008,  130:  2954-2955  
Further Information

Publication History

Publication Date:
23 July 2008 (online)


Significance

The synthesis of β-caryophyllene and coraxenolide A by Larionov and Corey is distinctive because it is a rare example of the use of planar chirality in natural product synthesis. Both enantiomers of (2Z,6E)-6-methylcyclonona-2,6-dienone (H) were prepared and used as chiral precursors for the synthesis of the (-)-β-caryophyllene and coraxeniolide A.

Comment

The absence of stereoselectivity in the reduction of C with NaBH4 was overcome by using the CBS reduction. Planar chiral H was obtained as a single enantiomer that is stable against racemization at room temperature owing to restricted C-C bond rotation in the 9-membered ring. By contrast, cyclononene racemizes in a few minutes at room temperature.