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Thermal Rearrangement of 5,6-Epimino-5,6-dihydro-β-ionone and Derivatives

✍ Scribed by Ernst Peter Müller

Publisher
John Wiley and Sons
Year
1985
Tongue
German
Weight
446 KB
Volume
68
Category
Article
ISSN
0018-019X

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✦ Synopsis

Abstract

Thermolysis of 5,6‐epimino‐5,6‐dihydro‐β‐ionone (1) and its N‐methyl derivative (2) leads to their monocyclic isomers 6 and 10, respectively, presumably due to a direct [1,5]‐H shift; on prolonged heating, these isomers are converted easily into pyrrole derivatives. In contrast, the thermoisomer 12 resulting from 5,6‐(N‐methoxycarbonyl)epimino‐5,6‐dihydro‐β‐ionone (3) by the same mechanism, does not undergo further ring transformation, but equilibrates with its more stable tautomer 13.

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