Stereospecific reduction of sapogen-3-ones
US7718792B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Apr 28, 2003 |
| Grant date | May 18, 2010 |
| Priority date | — |
| Expiry date | Mar 20, 2025 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC07J71/0005
- WIPO fieldOrganic fine chemistry
- WIPO sectorChemistry
Abstract
A method to stereospecifically prepare a steroidal sapogenin or a derivative thereof by reducing a 3-keto,5β-H steroidal sapogenin with a hindered organoborane or an organo-aluminium hydride. A 3β-hydroxy,5β-H steroidal sapogenin or derivative thereof may be prepared by reducing the 3-keto,5β-H steroidal sapogenin using as reducing agent a relatively highly hindered organoborane reagent or by SN 2 inversion of a 3α-hydroxy,5β-H steroidal sapogenin or derivative thereof. The organo-aluminium hydride may be used to prepare a 3α,5β-H steroidal sapogenin or derivative thereof. The invention provides a convenient route to useful steroidal sapogenins such as sarsasapogenin, episarsasapogenin, smilagenin, epismilagenin and esters thereof, from readily available or easily preparable starting materials (e.g. diosgenone, preparable from diosgenin).
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.