Synlett 1996; 1996(9): 827-828
DOI: 10.1055/s-1996-5617
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Switchover of the Diastereofacial Selectivity in the Michael Reaction of a Chiral Ester Enolate with α,β-Enone

Makoto Shimizu, Yoshio Onogawa, Tamotsu Fujisawa*
  • *Department of Chemistry for Materials, Mie University, Tsu, Mie 514, Japan, Fax +81-592-31-9471, mshimizu@chem.mie-u.ac.jp
Further Information

Publication History

Publication Date:
31 December 2000 (online)

1,4-Addition of ester enolates having cinchonyl group as a chiral auxiliary to α,β-unsaturated ketone was found to give either of the diastereomers by choosing a proper enolate metal species. The iodozinc enolate of isobutyrate gave 3S-ester after ester exchange of the initial adduct with MeOH in the presence of KOH, whereas the Li enolate in the presence of Me4Sn induced the reversal of the diastereoselectivity to give the corresponding 3R-isomer.

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