2005 Thiopyran derivatives R 0370 Proline-Catalyzed Ketone-Aldehyde Aldol Reactions Are Accelerated by Water. -Under optimized conditions the title reactions are accelerated by the addition of 1-10 equivalents of water. -(NYBERG, A. I.; USANO, A.; PIHKO*, P. M.; Synlett

Proline-catalyzed aldol reactions between acetone or 4-thianone and different aldehydes are accelerated by addition of 1-10 equivalents of water to the reaction medium, allowing stoichiometric aldol reactions to proceed at acceptable rates.

Enantioselective syntheses O 0031Effect of Additives on the Proline-Catalyzed Ketone-Aldehyde Aldol Reactions.-The highest yields and e.e. values are achieved with water (100-500 mol%) as an additive in stoichiometric aldehyde/ketone reactions. -(PIHKO*, P. M.; LAURIKAINEN, K. M.; USANO, A.; NYBERG, A. I.; KAAVI, J. A.; Tetrahedron 62 (2006) 2-3, 317-328; Dep. Chem. Technol., Helsinki Univ. Technol., SF-02015 Hut, Finland; Eng.) -Y. Steudel 21-027