Fragmentation of 3-oximino-4-chromanone

Heating either the methanesulfonate ester of 3-oximino-4-chromanone or 3-oximino-4-chromanone and an alternative acylating agent such as p-toluensulfonyl chloride or acetic anhydride in the presence of aqueous base afforded two major fragments: salicyclic acid and 2-carboxyphenoxyacetonitrile. These compounds are derived from two separate cleavage pathways involving the acylated oxime. In one pathway, fragmentation appears to be assisted by the ether ring oxygen; in the other, it is assisted by the alpha-carbonyl group of the oxime ester.