Dihydrotestosterone acetate

The route used to prepare the unsaturated 2 methyl androgen stenbolone provides yet a further illustration of the propensity for the formation of enolates at the 2 position. Thus reaction of dihydrotestosterone acetate (41-1) with formaldehyde and dimethylamine gives the Mannich product (41-2). Hydrogenolysis of that product gives the 2 methyl derivative (41-3) the relatively elevated temperature used for this last reaction suggests that the reaction may proceed via the methylene product... 

Fetizon et al.3 used this reaction in a new synthesis of A2-steroids from 3-keto-steroids. For example, dihydrotestosterone acetate (1) is converted in high yield into the 2a-bromoketone (2) with phenyltrimethylammonium perbromide (1, 855). The a-bromoketone is then heated for 3 hours with freshly distilled triethyl phosphite to give the enol phosphate (3). On reduction of (3) with lithium in liquid... 

In much the same vein, reaction of dihydrotestosterone acetate (7-1) with ethyl formate and sodium ethoxide gives the... 

Properties of substituted 4,5a-dihydrotestosterone esters, ethers, and acetals. 

The seminal work on steroid analyses using chiroptical detection was done by Djerrasi by the determination of hecogenin acetate in the presence of tigonenin acetate.Every steroid is chiral and therefore amenable to polarimetric detection after chromatographic separation. Chromophores are fairly uncommon, and analysis by ORD or CD is therefore less suitable. The only unsaturation in the cholesterol molecule, for example, is the isolated A -double bond, which has an absorbance maximum at 205 nm. Unsaturation coupled with chirality provides some selectivity, as ably demonstrated by the work of Potapov for analogs of progesterone Even simpler than that is the direct discrimination between the ketosteroids testosterone and dihydrotestosterone, which have opposite signs in methylene chloride solution (Fig. 6). 

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