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Synfacts 2008(5): 0533-0533  
DOI: 10.1055/s-2008-1072686
Organo- and Biocatalysis
© Georg Thieme Verlag Stuttgart · New York

Direct Crossed-Aldol Reaction of Acetaldehyde

Contributor(s): Benjamin List, Subhas Chandra Pan
Y. Hayashi*, T. Itoh, S. Aratake, H. Ishikawa
Tokyo University of Science, Japan
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Publication History

Publication Date:
23 April 2008 (online)

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Significance

The authors report an organocatalytic asymmetric direct crossed-aldol reaction of acetaldehyde. Diaryl prolinol 1 was found to be an effective catalyst and DMF the best solvent for this reaction. Due to the instability of the aldol products they were reduced to the corresponding diols. With 10 mol% of catalyst 1 and 5 equivalents of acetaldehyde, good to high yields (50-92%) and excellent enantioselectivities (er = 98:2 to >99:1) are obtained for different aromatic aldehydes. One aliphatic aldehyde was also used and reasonable enantioselectivity (er = 90:10) was obtained.