Dehydroepiandrosterone, conversion into

Roberts et al. (1961) first described the conversion of dehydroepian-drosterone sulfate into androsterone and 5/3-androsterone glucuronides in vivo, thereby establishing that dehydroepiandrosterone sulfate can be split in vivo and that there is a dynamic equilibrium dehydroepiandrosterone sulfate dehydroepiandrosterone (Fig. 4). The conversion of dehydroepiandrosterone sulfate into androsterone and 5 -androsterone sulfates can only exist via an indirect pathway (Baulieu et al., 1965) (Fig. 5), but dehydroepiandrosterone sulfate can be transformed both directly and indirectly into epiandrosterone sulfate (Fig. 6). 

The 1,4-addition of alkyl cyanocupratcs to epoxides to form cyclic a,ft-unsalurated ketones provides a stereoselective method for conversion of dehydro-. cpiandrosteronc into cholesterol (4) and other related steroids. Thus the keto epoxide 2 (obtained from dehydroepiandrosterone in 55% overall yield in three steps) reacts with lithium isohcxylcyanocupratc to give the adduct 3, which can be converted to cholesterol (4) in several known steps.27... 

I) Consider three structurally similar Cis steroids —testosterone, an-drostenedione, and dehydroepiandrosterone. Each of these compounds is secreted into the blood stream by glands, and after provoking its biochemical effect, is metabolized and excreted. If the only source of the plasma pool were provided by the glandular secretion of the hormone, then the secretion rate would be used to calculate the plasma concentration. However, the picture in the case of the three Ci steroids is complicated by the fact that the three compounds are peripherally interconvertible. Since both glandular secretion and peripheral conversion of precursors contribute to the plasma pool, the production rate is used to... 

Wittig-Horner reaction. This phosphonate has been used in a synthesis of progesterone (4) from dehydroepiandrosterone (2). One step in the conversion of (3) into (4) was an Oppenauer oxidation. The usual conditions (aluminum... 

Pic. 13. Transformations of dehydroepiandrostwone and dehydroepiandrosterone sulfate in the fetal and placental compartments. (I) Only a little conversion of DIIA into indro.stenedionc occurs in fetid testis. (2) Limited interconversion. DHA-S dehydro-cpiandrosterone sulfate DIIA dehydroepiandrc terone.

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