The semi-synthetic podophyllotoxin glycosides, VP-16-213 (1) and VM-26 (2) showing a marked clinical efficacy and the intriguing mechanisms of action have stimulated interest in the synthesis of new active analogues of the podophyllotoxin glycoside. The systematic chemical modification of podophyllotoxins was studied. 1) Aminoglycosidic lignan variants (6, 7, etc.) of 4'-O-demethy1-1-epipodophyllotoxin were synthesized by a stereoselective BF_3-catalyzed coupling of 5 with the corresponding aminosugar derivatives. N-Alkylaminoglycosyl analogues (8, etc.) of 1 were also derived from 6. 2) Syntheses of all possible diastereomers (1, 6, 8, and 15-23) of 1, 6 and 8 were achieved via optical resolution of (±)-podophyllotoxin by glycosidation with D- and L-sugars. 3) Glycosidic variants of 1-β-hydroxy-α-peltatin and 1-β-hydroxy-8-O-methyl-a-peltatin (24-26) were synthesized by glycosidation of 28 and 29 with the corresponding sugar derivatives. 4) The syntheses of carbocyclic lignan variants (34-37) of 4'-O-demethyl-1-epipodophyllotoxin were achieved by coupling of 5 with chiral aminocyclitols. 5) 1-O-(2-Aminoethyl) ethers of 4'-O-demethyl-1-epipodophyllotoxin (38-42, etc.) were synthesized by coupling of 5 with the corresponding 2-aminoethanol derivatives, and with ethylene glycol followed by reductive amination of its aldehyde. Among all derivatives synthesized, 6 and 8 were found to have superior antitumor activity to 1.