Method of making asymmetric DE ring intermediates for the synthesis of camptothecin and camptothecin analogs

摘要

The present invention is directed towards new methods of making DE ring intermediates of Formula (III), <IMAGE> (III) wherein Y is H or halogen and R is loweralkyl, which in turn are useful in methods of making camptothecin and camptothecin analogs. The present invention also provides new compounds useful in the methods of making compounds of Formula (III).