On reduction of α,β-unstaurated ketones and the respective allylic alcohols, bearing a phenylsulfonyl or phenylsulfanyl group in the α position. Hydroxy group-controlled stereoselective reduction of 3α- and 3β-hydroxy-4-(phenylsulfonyl)cholest-4-ene

Crystal Structure of Human Liver Δ4-3-Ketosteroid 5β-Reductase (AKR1D1) and Implications for Substrate Binding and Catalysis

“…Treatment with borohydride favors formation of the 3␤-allylic alcohol, and under harsher conditions, the 3␤,5␣-tetrahydrosteroid is formed (8,9). It is possible to generate a 5␤-cholestane from the corresponding ⌬ 4 -3-ketosteroid only if a large directing group is placed at C-4 or C-7 to direct the face of hydride addition or catalytic hydrogenation (10,11). Notably, AKR1D1 exclusively generates the reduced steroid bearing a thermodynamically less favorable 5␤-configuration.…”

Diastereoselective Approaches to trans-Hydrindane Derivatives − Total Synthesis of 8-(Phenylsulfonyl)de-A,B-cholestane Precursors to 25-Hydroxyvitamin D3

“…Model experiments on the reduction of an analogous vinyl sulfone located in a decalin ring system (a cholestane derivative) were encouraging and showed that (1) the steric course of reduction might depend upon the orientation of the hydroxy group and (2) the hydroxy group (in the 1,2-position to the phenylsulfonyl group) could ultimately be reduced to yield the corresponding saturated sulfone. [19] However, application of this reaction sequence to vinyl sulfides 17 and 19 appeared somewhat more complex, due to the presence of the additional double bond, oxidation of which would produce diastereomers. We therefore decided to proceed with oxidation and reduction steps without isolation of intermediates.…”

“…A vinyl sulfide with the hydroxy group in the α orientation (19,Scheme 4) was treated with m-CPBA (ca. 3.5 molequiv.)…”

Enantioselective Total Synthesis of a trans‐Hydrindane Rings/Side‐Chain Building‐Block of Vitamin D − Asymmetric Induction in an Acid‐Catalyzed Conjugate‐Addition Reaction

“…Finally, the tosyloxy/sulfone derivatives were reduced with LiAlH 4 . [47] A mixture of two compounds was obtained. The major product, separated by column chromatography (36% yield from 31), was identified as the required acetonide 35.…”