Synthesis 1971; 1971(5): 236-253
DOI: 10.1055/s-1971-21707
review
© 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.

Die Umsetzung von Carbonsäureestern mit Natrium in Gegenwart von Trimethylchlorsilan

Klaus RÜHLMANN*
  • *Sektion Chemie der Humboldt-Universität zu Berlin
Further Information

Publication History

Publication Date:
12 September 2002 (online)

The reaction of carboxylic acid esters with sodium in inert solvents (Bouveault-Blanc condensation) in the presence of trimethylchlorosilane is reviewed. By the addition of trimethylchlorosilane, which reacts with basic by-products, the reaction mixture is kept neutral. This completely prevents base-catalyzed side reactions such as ß-eliminations and Claisen- or Dieckmann-condensations. Trimethylchlorosilane has no effect, however, on side reactions which proceed via free-radical mechanisms. By addition of trimethylchlorosilane, the yields obtained in known acyloin syntheses can be increased and the scope of the original procedure considerably extended. The reaction products - bis-siloxy-alkenes - are either isolated or converted into acyloins by acid hydrolysis or alcoholysis. In several syntheses, they can also be directly used as "potential acyloins". Unlike a number of the corresponding acyloins, the bis-siloxy-alkenes can be stored under non-hydrolytic conditions for extended periods of time without undergoing decomposition.