18-Substituted Steroids. Part 8. An Improved Synthesis of 11β,18,21-Trihydroxypregn-4-ene-3,20-dione ('18-Hydroxycorticosterone')
'18-Hydroxycorticosterone' (1) has been prepared from 11β-formyloxy-20-hydroxypregn-4-en-3-one (6) by application of the 'hypoiodite' series of reactions , followed by acetoxylation at C-21 by lead tetra-acetate in acetic acid.Alkaline hydrolysis then gave 18-hydroxycorticosterone.