Androsta-3,5-dien-7-one

With dienones exchange of all potentially activated hydrogens is less certain. For example, in alkaline medium, androsta-3,5-dien-7-one (26) undergoes complete exchange, while only the 2,2,4-trideutero derivative... 

Most dienones that have been reduced have structures such that they cannot give epimeric products. However, reduction of 17 -hydroxy-7,17a-dimethyl-androsta-4,6-dien-3-one (63) affords 17 -hydroxy-7j9,17a-dimethylandrost-4-en-3-one (64), the thermodynamically most stable product, albeit in only 16% yield. The remainder of the reduction product was not identified. Presumably the same stereoelectronic factors that control protonation of the / -carbon of the allyl carbanion formed from an enone control the stereochemistry of the protonation of the (5-carbon of the dienyl carbanion formed from a linear dienone. The formation of the 7 -methyl compound from compound (63) would be expected on this basis. 

Figure 4.5 Structures of selected steroidal analytes 5a-androstan-17P-ol-3-one (1), 5P-androstan-17P-ol-3-one (2), 17a-methyl-5a-androstan-17P-ol-3-one (3), la-methyl-5a-androstan-17P-ol-3-one (4), testosterone (5), nandrolone (6), 1-testosterone (7), metenolone (8), 5a-androst-l-ene-3,17-dione (9), metandienone (10), 18-nor-17P-hydroxymethyl,17a-methyl-androst-l,4,13-trien-3-one (metandienone metabolite) (11), androsta-4,6-dien-17P-ol-3-one (12), androsta-4,9-dien-17P-ol-3-one (13), trenbo-lone (14), methyltrienolone (15), tetrahydrogestrinone (THG, 16), and stanozolol (17).

Figure 3.6 Structures of selected steroidal compounds testosterone (1), 5a-dihydrotestosterone (2), androsterone (3),etiocholanolone (4), 1-dehydrotestosterone (5), androsta, 6-dien-17p-ol-3-one (6), and 17a-methylandrosta-4,9(ll)-dien-17P-ol-3-one (7).

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