(F–) Anion exchange resins used as a polymer-supported reagent are a source of ‘naked’ fluoride and give use to clean SN2 reactions as shown by the preparation of epimerically pure 3-fluoro-steroids and of both diastereoisomers of ethyl 2-fluoropropionate. Fluoro-sugars are also prepared from the corresponding toluene-p-sulphonates. The remaining water of the resin enhances the basic behaviour of F–, as in phase-transfer catalyst techniques, but careful dehydration drives the reaction to clean substitution.
Anionic activation in polymer-supported reactions. Part 2. Stereochemical studies on the introduction of fluorine at chiral centres and in biologically significant molecules / S. Colonna, A. Re, E. Cesarotti, G. Gelbard. - In: JOURNAL OF THE CHEMICAL SOCIETY. PERKIN TRANSACTIONS. I. - ISSN 0300-922X. - 9(1979), pp. 2248-2252. [10.1039/P19790002248]
Anionic activation in polymer-supported reactions. Part 2. Stereochemical studies on the introduction of fluorine at chiral centres and in biologically significant molecules
E. CesarottiPenultimo
;
1979
Abstract
(F–) Anion exchange resins used as a polymer-supported reagent are a source of ‘naked’ fluoride and give use to clean SN2 reactions as shown by the preparation of epimerically pure 3-fluoro-steroids and of both diastereoisomers of ethyl 2-fluoropropionate. Fluoro-sugars are also prepared from the corresponding toluene-p-sulphonates. The remaining water of the resin enhances the basic behaviour of F–, as in phase-transfer catalyst techniques, but careful dehydration drives the reaction to clean substitution.Pubblicazioni consigliate
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