申请人:Gunning James Philip
公开号:US20060041119A1
公开(公告)日:2006-02-23
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).
一种立体特异性制备类固醇皂甙或其衍生物的方法,通过使用受阻有机硼烷或有机铝氢化物还原3-酮基、5β-H的类固醇皂甙。使用相对高度受阻的有机硼烷试剂还原3-酮基、5β-H的类固醇皂甙,或通过SN 2 反转3α-羟基、5β-H的类固醇皂甙或其衍生物,可制备3β-羟基、5β-H的类固醇皂甙或其衍生物。有机铝氢化物可用于制备3α、5β-H的类固醇皂甙或其衍生物。该发明提供了一种方便的途径,从易得到或易制备的起始材料(例如从蕃薯皂苷中制备的)制备有用的类固醇皂甙,例如山药皂甙、异山药皂甙、菝葜皂甙、异菝葜皂甙和它们的酯类。