| 摘要 |
<p>In one aspect, the invention provides a process for the preparation of compounds of Formula I wherein R<SUB>1 </SUB>is -CN, -OP, alkyl, aryl or heteroaryl; wherein P represents any suitable protecting group; and R<SUB>2 </SUB>is alkyl or aryl; by reacting a compound of Formula II wherein R<SUB>1 </SUB>is -CN, -OP, alkyl, aryl or heteroaryl; wherein P represents any suitable protecting group; and R<SUB>2 </SUB>is alkyl or aryl; with a reducing agent (e.g. sodium borohydride) in the presence of a metal halid (e.g. CeCl<SUB>3</SUB>) or a metal alkoxid (e.g. Ti(OiPr)<SUB>4</SUB>).</p> |
