Synfacts 2010(3): 0311-0311  
DOI: 10.1055/s-0029-1219325
Metal-Catalyzed Asymmetric Synthesis and Stereoselective Reactions
© Georg Thieme Verlag Stuttgart ˙ New York

Desymmetrization of Medium-Ring Cyclic Epoxides with SiCl4 and Chiral Mono-N-Oxide Lewis Base

Contributor(s): Hisashi Yamamoto, Zhi Li
A. V. Malkov*, M. R. Gordon, S. Stončius*, J. Hussain, P. Kočovský*
University of Glasgow and Loughborough University, UK
Further Information

Publication History

Publication Date:
18 February 2010 (online)

Significance

The authors discovered a chiral bipyridine mono-N-oxide-catalyzed SiCl4-mediated enantioselective desymmetrization of cyclic meso-epoxides. Although the enantioselectivities for six- and seven-membered epoxides were moderate, this reaction provided excellent enantioselectivities for larger ring systems. Also, the special work-up conditions prevent the racemic ring opening by HX.