| 摘要 |
PURPOSE:To prepare the titled compound useful as a carcinostatic agent, in high yield and purity, in a short time, by alcoholyzing a compound having halogenoacetyl group and the structure corresponding to the objective compound in the presence of a catalyst, thereby removing the halogenoacetyl group from the starting compound. CONSTITUTION:The 4'- halogenoacetyl -4'- demethyl -epipodophyllotoxin-beta-D-2, 3- di-O-halogenoacetyl-4,6-O-ethylidene glucoside of formula I [R is halogenoacetyl of formula -COCH2X (X is halogen)] is subjected to the alcoholysis with e.g. methanol, in the presence of a catalyst [e.g. ZnCl2, Zn powder, (CH3COO)2Pb, etc.] (preferably 10-150wt%, based on the compound of formula I ), preferably for 1-5hr. The halogenoacetyl group is removed by the alcoholysis, and the objective compound of formula II can be obtained. The starting compound of formula I can be prepared from 4'-demethyl-epipodophyllotoxin which is drived from a plant-originated actitumor substance, podophyllotoxin.
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