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Published on: August 10, 2016
Evidence for a Sigmatropic and an Ionic Pathway in the Winstein Rearrangement
Amy A Ott1, Mary H Packard1, Manuel A Ortuño1
1Department of Chemistry , University of Minnesota Twin Cities , Minneapolis , Minnesota 55455 , United States.
Abstract:
The spontaneous rearrangement of allylic azides is thought to be a sigmatropic reaction. Presented herein is a detailed investigation into the rearrangement of several allylic azides. A combination of experiments including equilibrium studies, kinetic analysis, density functional theory calculations, and selective 15N-isotopic labeling are included. We conclude that the Winstein rearrangement occurs by the assumed sigmatropic pathway under most conditions. However, racemization was observed for some cyclic allylic azides. A kinetic analysis of this process is provided, which supports a previously undescribed ionic pathway.
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