合成路线1

The partial demethylation of (±)-podophyllotoxin (I) with HBr in ether - dichloromethane, followed by alkaline hydrolysis with BaCO3 in aqueous acetone, gives (±)-4'-O-demethyl-1-epipodophyllotoxin (II), which is partially esterified with chloroacetyl chloride and pyridine, yielding (±)-4'-O-chloroacetyl-4'-O-demethyl-1-epipodophyllotoxin (III). The glycosidation of (III) with 2-(benzyloxocarbonylamino)-3-O-chloroacetyl-2-deoxy-4,6-O-ethylidene-beta-D-glucopyranose (IV) by means of BF3 ethearate in dichloromethane affords (±)-1-O-[2-(benzyloxycarbonylamino)-3-O-chloroacetyl-2-deoxy-4,6-O-ethylidene-beta-D-glucopyranosyl]-4'-O-(chloroacetyl)-4'-O-demethyl-1-epipodophyllotoxin (±)-(V) which, after separation of the diastereomers and elimination of the protecting groups with zinc acetate in refluxing methanol and H2 over Pd/C in ethyl acetate - ethanol, gives 1-O-(2-amino-2-deoxy-4,6-O-ethylidene-beta-D-glucopyranosyl)-4'-O-demethyl-1-epipodophyllotoxin (VI). Finally, this compound is methylated with formaldehyde and sodium cyanoborohydride in methanol. The sugar moiety has been obtained as follows: The reaction of 2-(benzyloxycarbonylamino)-2-deoxy-beta-D-glucopyranose (VII) with acetaldehyde and concentrated H2SO4 gives 2-(benzyloxycarbonylamino)-2-deoxy-4,6-O-ethylidene-beta-D-glucopyranose (VIII), which is then esterified with chloroacetyl chloride to (IV).