Periselectivity between the [1,4] and [3,3] thermal sigmatropic rearrangements of 2-allyloxypyridine N-oxides

1990; Issue: 6 Linguagem: Inglês

10.1039/p19900001623

ISSN

2050-8255

Autores

David Alker, W. David Ollis, Hooshang Shahriari-Zavareh,

Tópico(s)

Synthesis and Reactivity of Heterocycles

Resumo

Thermal rearrangement of 2-allyloxypyridine N-oxides (4a–c) yields N-allyloxy-2-pyridones (5a–c) and 3-allyl-N-hydroxy-2-pyridones (6a–c). These transformations are shown to be regiospecific and on this basis it is proposed that the reactions involve concerted [1,4] and [3,3] sigmatropic rearrangements. Supporting evidence based on solvent effects, temperature effects, and substituent effects is given.

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