Anomalous cleavage of isoxazoline rings.

FASCIO MIRTA L.; GELABERT, LAURA I.; D'ACCORSO NORMA B.

Curitiba - brasil

Congreso; IX Brazilian Meeting on Organic CSynthesis; 2001

Sociedad Brasilera de Química

The isoxazoline rings have been used as a key building block in the total synthesis of natural and unnatural compounds. Its interaction with the appropriate sort of reagent can access to different bifunctional systems. For example, the cleavage of the N-O bond, yield initially a â-hydroxy imine that is then hydrolysed to â-hydroxy ketone.â-hydroxy imine that is then hydrolysed to â-hydroxy ketone. With the aim of obtained polyfunctionalized carbohydrate derivatives, we undertook the isoxazolinic rings cleavage, of the same compounds which we had recently described.  The hydrogenolysis of the isoxazoline rings, using Pd/C as catalyst, give the â-hydroxy ketones, as is described in literature. 3 The treatment of our isoxazolines in these conditions produced two compounds, that we characterized as the oxime and ketone, which resulted from the C-O bond cleavage. We have observed a similar cleavage when we performed the tandem mass spectrometry studies of these kind of compounds. We have observed a similar cleavage when we performed the tandem mass spectrometry studies of these kind of compounds. We have observed a similar cleavage when we performed the tandem mass spectrometry studies of these kind of compounds.