L’anion fluorure comme base en synthèse organique: methylénation des cycloalcanediols-1,2 par le dichlorométhane; nouvelle méthode de préparation des diméthylène-2,3 norbornanes

1,2-cycloalcanediols heated in CH2Cl2/DMF (or DMSO) containing an excess of CsF furnish the corresponding 1,3-dioxolanes when the hydroxyl groups are in a cis-eclipsed conformation. This technique can be applied to sensitive diols (e. g. 5,6-dimethylidene- exo,exo-2,3-norbornanediol) that are not c...

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Bibliographic Details
Main Authors: Jean-Pierre Hagenbuch, Pierre Vogel
Format: Article
Language:deu
Published: Swiss Chemical Society 1977-04-01
Series:CHIMIA
Online Access:https://www.chimia.ch/chimia/article/view/9346
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Summary:1,2-cycloalcanediols heated in CH2Cl2/DMF (or DMSO) containing an excess of CsF furnish the corresponding 1,3-dioxolanes when the hydroxyl groups are in a cis-eclipsed conformation. This technique can be applied to sensitive diols (e. g. 5,6-dimethylidene- exo,exo-2,3-norbornanediol) that are not catechols. Double elimination of HCl from 2,3-bis(chloromethyl)-norbornanes occurs in the same conditions, thus uncovering a new method of preparation of 2,3-dimethylidene-norbornanes in mild conditions. Methylenation of 1,2-diols can be carried out by CH2C12/KOH/phase transfer catalyst; in these conditions the elimination of HCl from trans-5,6-bis (chloromethyl)-exo,exo-2,3-norbornane-diol does not occur.
ISSN:0009-4293
2673-2424