- Generation and reactions of ammonium ylides in basic two-phase systems: Convenient synthesis of cyclopropanes, oxiranes and alkenes substituted with electron-withdrawing groups
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Quaternary ammonium salts 1 react with electrophilic alkenes 2, aromatic aldehydes 3 and alkylating agents 4, in the presence of 50% aq sodium hydroxide or powdered potassium carbonate, in dichloromethane, to form cyclopropanes 5, oxiranes 6 and alkenes 7
- Jończyk, Andrzej,Konarska, Anna
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- Generation and reaction of ammonium ylides in basic two-phase systems
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Reaction of the quaternary ammonium salts 2a-i with electrophilic alkenes 3, active alkylating agents 7 or aromatic aldehydes 11, carried out in basic two-phase systems A-D, afforded cyclopropanes 4, cyanoalkenes 8 or cyanooxiranes 12 respectively, via the corresponding ammonium ylides 2+-. The method is very simple, and gives cyclopropanes 4 and cyanoalkenes 8 in high yield. Under similar conditions, 1-cyanodienes 8aa,ba were cyclopropanated at the γ,δ-double bond with formation of vinylcyclopropanes 9a,b. The stereochemistry of the prepared cyclopropanes was elucidated from literature, 1H NMR spectroscopic data, NOE experiments or X-ray single crystal analysis. Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005.
- Kowalkowska, Anna,Sucholbiak, Dorota,Jonczyk, Andrzej
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p. 925 - 933
(2007/10/03)
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- Rearrangements of substituted 3-aza-1,2,5-hexatrienes. 3. The scope and versatility of an extremely mild 3-aza-Cope reaction
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An investigation of the [3,3]-sigmatropic reaction of substituted 3-aza-1,2,5-hexatrienes to give 4-pentenenitriles is presented. This reaction has been found to occur under a wide variety of reactions conditions (10 are reported) starting from readily av
- Walters, Michael A.,Hoem, Andrew B.,McDonough, Colleen S.
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