ORGN 114 |
| Alice E. Lurain, Patrick J. Carroll, and Patrick J. Walsh. Department of Chemistry, University of Pennsylvania, 231 S. 34th Street, Philadelphia, PA 19104 |
| We have developed a one-pot procedure for the asymmetric synthesis of a synthetically challenging class of acylic secondary epoxy alcohols with three contiguous stereocenters from simple achiral starting materials. The epoxy alcohols are synthesized via a tandem catalytic asymmetric vinylation of an aldehyde coupled with a diastereoselective epoxidation reaction. A vinylzinc reagent generated in situ undergoes enantioselective addition to an aldehyde in the presence of a zinc catalyst to provide an allylic zinc alkoxide. This species is then epoxidized by addition of dioxygen and a titanium-tartrate catalyst to give epoxy alcohols with excellent enantioselectivities and with diastereoselectivities up to 4.5:1 in favor of the threo diastereomer. The system described herein represents a significant advance in terms of synthetic efficiency and selectivity. |
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Asymmetric Reactions and Syntheses, Metal-Mediated Reactions, Materials, Molecular Recognition
8:00 PM-10:00 PM, Sunday, August 22, 2004 Pennsylvania Convention Center -- Hall D, Poster
Division of Organic Chemistry |