(+)-(<i>R</i>,<i>Z</i>)-5-Muscenone and (−)-(<i>R</i>)-Muscone by Enantioselective Aldol Reaction and Grob Fragmentation
作者:Charles Fehr、Andrea K. Buzas、Oliver Knopff、Jean-Yves de Saint Laumer
DOI:10.1002/chem.200902774
日期:2010.2.22
(+)‐(R,Z)‐5‐Muscenone ((R)‐1) was synthesized by an enantioselective aldol reaction, catalyzed by new ephedrine‐type Ti reagents (up to 70 % enantiomeric excess). Substrate‐directed diastereoselective reduction of the aldol product and Grob fragmentation of the tosylate of the resultant 1,3‐diol afforded (+)‐1. This approach also gave access to (−)‐(R,E)‐5‐muscenone and (−)‐(R)‐muscone.
(+)‐(R,Z)‐5‐Muscenone((R)‐1)是通过新的麻黄碱型Ti试剂(最多70%对映体过量)催化的对映选择性羟醛反应合成的。生成的1,3-二醇的底物定向的非对映选择性降低了羟醛产物和甲苯磺酸酯的Grob片段,得到了(+)- 1。这种方法还可以访问(−)‐(R,E)‐5香cen酮和(−)‐(R)‐麝香酮。