The selective insertion of a fluorine atom in the molecular skeleton of biologically active compounds often leads to increased selectivity, lower toxicity and dosage, and broad-spectrum activity. For this reason, the synthesis of four 10-β-fluorine substituted 1,4- estradien-3-oxo derivatives has been carried out and their mass spectrometric behaviour studied, using different ionization techniques, e.g. Fast Atom Bombardment (FAB) and Electron Impact (ED. What is generally observed with respect to the nonfluorinated analogues is the weakening of C(9)C(10) bond, due to the higher stability of the +C(10)F cation. This reflects a higher abundance of the fragments arising from further cleavage of the C(7)C(8) bond. Furthermore, for fluorinated compounds an easy H2O loss is observed, showing that in such cases the keto-enol tautomerism is strongly shifted in the enol direction.
Massspectrometricbehaviour of some fluorinesubstituted 1,4-estradien-3-oxo steroids
RESNATI, GIUSEPPE;
1992-01-01
Abstract
The selective insertion of a fluorine atom in the molecular skeleton of biologically active compounds often leads to increased selectivity, lower toxicity and dosage, and broad-spectrum activity. For this reason, the synthesis of four 10-β-fluorine substituted 1,4- estradien-3-oxo derivatives has been carried out and their mass spectrometric behaviour studied, using different ionization techniques, e.g. Fast Atom Bombardment (FAB) and Electron Impact (ED. What is generally observed with respect to the nonfluorinated analogues is the weakening of C(9)C(10) bond, due to the higher stability of the +C(10)F cation. This reflects a higher abundance of the fragments arising from further cleavage of the C(7)C(8) bond. Furthermore, for fluorinated compounds an easy H2O loss is observed, showing that in such cases the keto-enol tautomerism is strongly shifted in the enol direction.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
