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Ring cleavage reactions of 3‐ and 5‐non‐substituted isoxazoles
Author(s) -
Alberola A.,
González A. M.,
Guerra D.,
Pulido F. J.
Publication year - 1982
Publication title -
journal of heterocyclic chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.321
H-Index - 59
eISSN - 1943-5193
pISSN - 0022-152X
DOI - 10.1002/jhet.5570190519
Subject(s) - chemistry , cleavage (geology) , nucleophile , ring (chemistry) , medicinal chemistry , iodide , stereochemistry , organic chemistry , catalysis , geotechnical engineering , fracture (geology) , engineering
5‐Methylisoxazoles with electron‐accepting groups at C‐4 (1a‐c) and 2,3‐dimethylisoxazolium iodide (II) undergo ring cleavage when treated with organic bases. The nature of the open chain products which were obtained (stable enolates, β‐diketones, esters) depends on the group at C‐4 and the strength of the base. In some of these processes aromatic aldehydes were used in order to determine the competition between the condensation and the cleavage reaction. The mechanism of the nucleophilic ring cleavage of II is also shown.