PDF herunterladen
Synthesis 1988; 1988(4): 278-280
DOI: 10.1055/s-1988-27542
paper
© Georg Thieme Verlag, Rüdigerstr. 14, 70469 Stuttgart, Germany. All rights reserved. This journal, including all individual contributions and illustrations published therein, is legally protected by copyright for the duration of the copyright period. Any use, exploitation or commercialization outside the narrow limits set by copyright legislation, without the publisher's consent, is illegal and liable to criminal prosecution. This applies in particular to photostat reproduction, copying, cyclostyling, mimeographing or duplication of any kind, translating, preparation of microfilms, and electronic data processing and storage.

Enantiotopic-Group Differentiation. Asymmetric Monoesterification of Malonic Acids Using Cinchona Alkaloid Derivatives

Jun Hiratake* , Kayoko Shibata, Naomichi Baba, Jun'ichi Oda
  • *Institute for Chemical Research, Kyoto University, Uji, Kyoto 611, Japan
Weitere Informationen

Publikationsverlauf

Publikationsdatum:
20. August 2002 (online)

  als PDF herunterladen  Lizenzen und Reprints Alle Artikel dieser Rubrik

2,2-Dimethyl-5-methyl-5-phenyl-4,6-dioxo-1,3-dioxane (1) was cleaved asymmetrically, by nucleophilic attack of primary alkoxide ions, paired with N-benzylquaternary ammonium cations, derived from cinchona alkaloids, to give optically active monoalkyl malonates 3 with moderate setereoselectivity. The ester group of 3 was selectively reduced to afford optically active α-methyltropic acid (5) in good yield. The relationship between the structure of ammonium cations and the direction of stereoselectivity is described.

      >