Synthesis of New Conjugates of Modified Podophyllotoxin and Stavudine

To find podophyllotoxin compounds with superior bioactivitiy and less toxicity, a series of novel conjugates of ring‐ A ‐modified 4‐epipodophyllotoxin and stavudine with amino acids as spacers were synthesized, i.e. , the N ‐[(2′,3′‐didehydro‐3′‐deoxythymidin‐5′‐ O ‐yl)carbonyl]‐substituted L ‐amino acid rel ‐(3a R ,4 S ,9 R ,9a R )‐1,3,3a,4,9,9a‐hexahydro‐6,7‐dimethoxy‐1‐oxo‐9‐(3,4,5‐trimethoxyphenyl)naphtho[2,3‐ c ]furan‐4‐yl esters 8a – 8f .