Methods for preparing 17-alkynyl-7-hydroxy steroids and related compounds-2

A process for preparation of 17α-ethynyl-androst-5-ene-3β,7β,17β-triol essentially free of 17α-ethynyl-androst-5-ene-3β,17β-diol comprising the steps of

• (a) contacting a suitably protected androst-5-en-7,17-dione having the structure
• with a reducing agent to convert the ═O (ketone) functional group at position 7 to hydroxy predominately in the β-configuration;
• (b) converting the oxime at position 17 in the reaction product from step (a) to the ═O (ketone) functional group;
• (c) converting the acyloxy group in the reaction product from step (b) to 3β-hydroxy;
• (d) converting the hydroxy groups at positions 3 and 7 in the product from step (c) to Me3SiO— groups;
• and
• (e) contacting the reaction product from step (d) with lithium trimethylsilyl-acetylide to introduce an ethynyl substituent at position 17 predominately in the α-configuration by addition of the acetylide to the ═O (ketone) functional group at position 17,
• wherein 17α-ethynyl-androst-5-ene-3β,7β,17β-triol is obtained essentially free of 17α-ethynyl-androst-5-ene-3β,17β-diol.