The present invention is directed to a process for the preparation of an enantiomerically enriched compound of formula II
wherein,
R1, R2 and R3 are each independently selected from hydrogen, halogen, substituted or unsubstituted lower alkyl or substituted or unsubstituted aryl;
X is -C(=O)-Z or -Y, wherein -Y is selected from -CH2-OR4, -CH2-halogen or - CH2-NR6R7;
wherein
Z is selected from -NR6R7 or -OR5, wherein R5 is selected from hydrogen, substituted or unsubstituted lower alkyl or ester activating group;
R4 is selected from hydrogen, hydroxyl protecting group or hydroxyl activating group;
R6 and R7 are each independently selected from hydrogen, amino protecting group, amido protecting group or substituted or unsubstituted lower alkyl;
which comprises an enantioselective addition with a thienyl zinc reagent, in the presence of a chiral ligand.
本发明涉及一种富含对映体的式 II 化合物的制备方法
其中
R1、R2 和 R3 各自独立地选自氢、卤素、取代或未取代的低级烷基或取代或未取代的芳基;
X是-C(=O)-Z或-Y,其中-Y选自-
CH2-OR4、- -卤素或- -NR6R7;
其中
Z 选自-NR6R7 或-OR5,其中 R5 选自氢、取代或未取代的低级烷基或酯活化基团;
R4 选自氢、羟基保护基团或羟基活化基团;
R6 和 R7 各自独立地选自氢、
氨基保护基团、
氨基保护基团或取代或未取代的低级烷基;
其中包括在手性
配体存在下与
噻吩锌试剂进行对映选择性加成。