ON THE SYNTHESIS OF SILOXANES. XXIV. NUCLEOPHILIC SUBSTITUTION REACTIONS OF 2-FUNCTIONAL 1,3-DIOXA-2,4,7-TRISILACYCLOHEPTANES AND 1,3-DIOXA-2,4,8-TRISILACYCLOOCTANES

Abstract

2-Hydrogen-1,3-diоха-2,4,7-tгisilасусlohерtаnеs and 2-hydrogen-1,3-diоха-2,4,8-tгisilасусlоосtаnеs, each as a mixture of three configurational isomers, were synthesized and halogenated with chlorine and bromine in the presence of pyridine. The stereochemical course of the halogenation reactions was studied by gas chromatography. 2-Сhlorо-2,4,7-tгimethуl- 4,7-bis(trimеthуlsiloxy)-1,3-dioxa-2,4,7-trisilacyсloheptanes and 2-chloro-2,4,7-trimethyl-4,7-diphenyl-1,3-dioxa-2,4,7-trisilacycloheptanes reacted with alcohols in the presence of pyridine, triethylamine or 2,6-dimеthуlpуridinе. Gas chromatography, ¹Н NMR and ²⁹Si NMR spectroscopy were used to investigate the stereochemistry of these substitution reactions. It has been found that all reactions proceed with retention of configuration and that the differences of the relative reactivities of the configurational isomers were distinctly smaller than those observed for reactions of the configurational isomers of functional cyclotrisiloxanes.

How to Cite
Rühlmann, K.; Jähnichen, S.; Scheim, U.; Scheller, D. Chem. Heterocycl. Compd. 1996, 32, 1367. [Khim. Geterotsikl. Soedin. 1996, 1590.]

For this article in the English edition, see DOI https://doi.org/10.1007/BF01169967