ISSN:
0018-019X
Keywords:
Chemistry
;
Organic Chemistry
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
Notes:
The course of the catalytic hydrogenation and isomerization (H2/Raney-Ni/dioxane or H2/Pd/C/EtOH) of Δ5.7-, Δ7-, Δ8-, and Δ8(14)-steroid olefins was shown to depend strongly on the configuration at C(13). The known hydrogenation/isomerization of reactions of Δ5.7-dienes in the 13β-series to Δ7-(H2/Raney-Ni/dioxane) and Δ8(14)-olefins (H2/Pd/C/EtOH) were also confirmed in the 3β, 19-epoxy-13β- and 3-Oxo-19-acetoxy-13β-steroid series (e.g. 32 → 35 → 37, Scheme 3). On the other hand, in the corresponding 13α-steroid series the same reactions afforded the Δ7-. and the Δ8-olefins (mixture of products with H2/Raney-Ni/dioxane; quantitatively the Δ8-compounds with H2/Pd/C/EtOH; s. e.g. Scheme 3). A similar dependence on the C(13) configuration was observed in the allylic oxidation of these olefins with SeO2 (Fieser's test, see Table), and in the acid catalyzed opening of the 7α, 8α-epoxides (e.g. 60 → 62 + 63 in the 13β-series, and 56 → 64 + 65 in the 13α-series, Scheme 8).
Additional Material:
1 Tab.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/hlca.19790620825
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