Patent ID: 9163059
Filing Date: 2015-10-20
Classification: C07J

Abstract:
1. 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 Me (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.