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Synfacts 2007(12): 1282-1282  
DOI: 10.1055/s-2007-991350
Metal-Catalyzed Asymmetric Synthesis and Stereoselective Reactions
© Georg Thieme Verlag Stuttgart · New York

Catalytic Enantioselective Tautomerization of Isolated Enols

Contributor(s): Hisashi Yamamoto, Matthew B. Boxer
C. Fehr*
Firmenich SA, Geneva, Switzerland
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Publication History

Publication Date:
22 November 2007 (online)

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Significance

This paper describes a nice unique method involving enantioselective tautomerization and protonation of isolated enols. Using catalytic lithiated chiral amino alcohol (1), slow addition of the isolated enol followed by warming from -78 °C to -40 °C and subsequent quenching with 5% aqueous HCl afforded the desired ketone with good ee. A nonlinear effect was observed pointing to higher order mixed aggregates being responsible for the asymmetric induction.