Synthesis of isomeric 5α-androstane-3,15,17β-triols
3α-Acetoxy-16α-bromo-5α-androstan-17-one (1) was converted into 16α-bromo-17,17-ethylenedioxy-5α-androstan-3α-ol (2), which was dehydrobrominated and hydrolysed to give 3α-hydroxy-5α-androst-15-en-17-one (5). Addition of benzyl alcohol to the Δ15-3α-ol (5) followed by hydrogenolysis yielded 3α, 15β-dihydroxy-5α-androstan-17-one (7). This was converted into 5α-androstane-3α, 15β, 17β-triol (8). Similarly 5α-androstane-3β, 15β, 17β-triol (10) was prepared from 3β-hydroxy-5α-androst-15-en-17-one (3). Hydroboration of 5α-androst-14-ene-3α, 17β-diol (12) afforded 5α-androstane-3α, 15α-17β-triol (13). The spectral properties of 5α-androstane-3,15,17β-triols are markedly affected by the configuration of the hydroxy-group at C-15.