RESUMEN
<p><b>AIM</b>To design and synthesize some cephalotaxine and drupacine derivatives with different substituentes on C3'-N of taxol side chain.</p><p><b>METHODS</b>Protective side chain acid VI (4'S,5'R) was prepared from optically active (2'R,3'S) methyl beta-phenyl glycidate I in five steps. The desired acids were coupled with cephlotaxine and drupacine respectively in the presence of 2-DPC/DMAP, followed by acidic hydrolysis and acylating to give novel alkloid esters with different substitutes on C3'-N.</p><p><b>RESULTS</b>The seven new esters were studied for antitumor activity, the results showed that the antitumor activity was influenced by the substituentes on C3'-N.</p><p><b>CONCLUSION</b>It might provide some rational basis for further structral modification.</p>