Enantioselective Epoxidation of Conjugated cis-Enynes by Chiral
Dioxirane
Christopher P. Burke andYian Shi*
Department of Chemistry, Colorado State University, Fort Collins, Colorado 80523
yian@lamar.colostate.edu
Received February 2, 2007
Abstract:
This paper describes a highly chemo- and enantioselective epoxidation of conjugated cis-enynes using
readily available glucose-derived ketone 2 as catalyst and Oxone as oxidant to form cis-propargyl epoxides
in high ee's. The interaction between the alkyne group of the substrate and the oxazolidinone moiety of
the ketone catalyst as well as the interactions between the substituents on enynes and the oxazolidinone
moiety of the ketone catalyst are important for the stereodifferentiation.
