title: 18-substituted steroids. Part 4. A chemical synthesis of 3 alpha,18,21-trihydroxy-5 beta-pregnan-20-one 18--20-hemiacetal (18-hydroxy-tetrahydro-DOC).
abstract: 3 alpha,18,21-Trihydroxy-5 beta-pregnan-20-one 18 leads to 20-hemiacetal (18-hydroxy-tetrahydro-DOC) has been prepared from 3 alpha-acetoxy-5 beta-pregnan-20-one by reduction to the 20 beta-alcohol, application of the 'hypoiodite' reaction [Pb(OAc)4-I2-hv] with subsequent steps leading to the 18-hydroxy-20-ketone (as hemiacetal), and C-21 acetoxylation [Pb(OAc)4] followed by hydrolysis.
mesh_terms: D015070:18-Hydroxydesoxycorticosterone / Q000031:analogs & derivatives* / Q000138:chemical synthesis; D003900:Desoxycorticosterone / Q000031:analogs & derivatives*
chemical_list: D015070:18-Hydroxydesoxycorticosterone; C023801:3 alpha,18,21-trihydroxy-5 beta-pregnan-20-one 18-20-hemiacetal; D003900:Desoxycorticosterone