Mitsunobu reactions with methanesulfonic acid; The replacement of equatorial hydroxyl groups by azide with net retention of configuration

✍ Scribed by Anthony P. Davis; Stephan Dresen; Laurence J. Lawless

• Book ID: 104257246
• Publisher: Elsevier Science
• Year: 1997
• Tongue: French
• Weight: 208 KB
• Volume: 38
• Category: Article
• ISSN: 0040-4039
• DOI: 10.1016/s0040-4039(97)00886-1

✦ Synopsis

Treatment of equatorial cyclohexanols with Ph3P/DEAD/MsOH gives clean conversion to the axial mesylates. Subsequent reaction with NaN3 gives the equatorial azides in overall yields of 74-87%. Axial hydroxyl groups are not affected, allowing the regioselective conversion of methyl cholate into a 3ct-azidodiol intermediate for steroid-based synthetic receptors.