| Abstract: | Elimination of acetic acid from the molecular ions of the epimeric androstanylacetates is investigated applying specific 2H-labelling and analysis of metastable transitions. Only 17β-androstanylacetate eliminates acetic acid in a 1,2-fashion to an extent of 16%. This contribution is shown to be a specific cis-elimination and after comparison with water-elimination in the corresponding alcohol a McLafferty type mechanism is attributed, which then appears to require a planar transition state. |
