Synthesis 2005(17): 2906-2912  
DOI: 10.1055/s-2005-872167
PAPER
© Georg Thieme Verlag Stuttgart · New York

Addition of Dilithio Derivatives of N-Monosubstituted Propanamides to Aldehydes: Stereochemistry, Scope and Limitations

Glen C. Gullicksona, Mushtaq A. Khanb, Jessica A. Waltersa, Russell G. Baughmanc, David E. Lewis*a,b
a Department of Chemistry, University of Wisconsin - Eau Claire, Eau Claire, WI 54702, USA
b Department of Chemistry & Biochemistry, South Dakota State University, Box 2202, Brookings, SD 57007, USA
c Division of Science, Truman State University, Kirksville, MO 63501, USA
Fax: +1(715)8364979; e-Mail: lewisd@uwec.edu;
Further Information

Publication History

Received 22 November 2004
Publication Date:
12 August 2005 (online)

Abstract

The dilithio derivatives of N-monosubstituted propanamides are formed as a mixture of stereoisomers in which the Z(O)-isomer is significantly favored by the reaction between the amide and butyllithium in THF-Et2O at 0 °C. Addition of the dilithio compound to aldehydes results in a mixture of the syn and anti aldols in near equal quantities, and in the recovery of up to 30% of the unreacted amide. The reaction outcome is essentially unaffected by time and temperature. Added zinc chloride changes the isomer ratio, but reduces chemical yields dramatically. The results are interpreted in terms of addition through three isomeric Zimmerman-Traxler-type transition states.

1

Address correspondence to this author at Department of Chemistry, University of Wisconsin - Eau Claire, Eau Claire, WI 54702-4004, USA.

14

Baughman, R. G.; Gullickson, G. C.; Khan, M. A.; Lewis, D. E. Acta Crystallogr. C., submitted for publication.