Synthesis and study of the labeling of pregnenolone and progesterone specifically tritiated at the 17 position

The action of tritiated acetic acid on 17-bromopreg-3_H] nenolone acetate treated with zinc metal dust produces 17 pregnenolone acetate which is then hydrolyzed to form 17 3_H] pregnenolone.The flavobacterium dehydrogenans transforms the 17-bromopregnenolone into 17-bromoprogesterone which can also be tritiated by tritiated acetic acid to obtain 17 3_H] progesterone. The study of the label distribution by different analytic techniques (I.R., nuclear magnetic resonance, mass spectrometry) as well as the. chemical and selective biochemical reactions indicate a specific labeling higher than 85% on the 17 position.