Steroid Total Synthesis—Hydrochrysene Approach. XIV.¹ The Synthesis of dl-18-Norepiandrosterone and dl-18-Nortestosterone²

Enantiomeric Steroids: Synthesis, Physical, and Biological Properties

“…They mention the action of 3α- and 3β-hydroxysteroid dehydrogenase from Comamonas testosteroni (Pseudomonas Testosteroni ) on two racemic substrates obtained by total synthesis: rac -18-nor-5β-androstan-3α,17β-diol 132 and rac -18-nor-5β,13α-androstane-3α,17α-diol 133 , Figure . They found that the α-dehydrogenase oxidizes the C-3 hydroxyl group of both racemates, so the α-dehydrogenase is not enantioselective, and β-dehydrogenase oxidizes only one enantiomer at C-17, the nat -steroid as interfered from the enzyme specificity . The kinetics parameters remain to be determined.…”

“…They found that the R-dehydrogenase oxidizes the C-3 hydroxyl group of both racemates, so the R-dehydrogenase is not enantioselective, and β-dehydrogenase oxidizes only one enantiomer at C-17, the nat-steroid as interfered from the enzyme specificity. 50 The kinetics parameters remain to be determined.…”

Designing Total Syntheses

“…Not all biological resolutions are successful, however, as in some cases both enantiomers are transformed and a racemic product results; examples are the action of Flavobacterium dehydrogenans on 170 [134], of Cunninghamella blakeseeana on 8-aza-D-homoestradiol 3-methyl ether [137], and of the 3a-hydroxysteroid dehydrogenase from Pseudomonas testosteroni on 166 [135]. Following the pioneering work on C-llhydroxylation by Peterson and colleagues [138], a large number of microbiological transformations of steroids have been performed [139], some of which may yet be adapted to resolutions.…”

Cd → BCD → Abcd

“…Indeed, (iZ-testosterone was very early synthesized from 28 [52,61]. Later work modified the procedure and produced Z-testosterone and cZZ-isotestosterone [62] in addition to ίΖΖ-18-nortestosterone [63,64]. Other natural products to be prepared included dZ-progesterone [65,66], dZ-cholesterol [66,67], conessine [53,66], and veratramine [68][69][70].…”