| 摘要 |
<p>A new class of antitumoral anthracyclines glycosides of the general formula I and II: <IMAGE> wherein R<1> = H, OCH3 and R<2> is H, OH, is described. The used starting material is 4'-epi-daunorubicin or its 4-demethoxy analogue, which, after protection of the amino group on the sugar moiety as benzophenone Schiff base, are reacted with trifluoromethanesulfonic anhydride to obtain the corresponding 4'-epi-4'-O-trifluoromethanesulfonates from which, after treatment with n-tetrabutyl ammonium fluoride and a subsequent mild acidic hydrolysis of the N-protecting group, the daunorubicin derivatives of formula I and II are obtained as a mixture of free bases. A chromatography on a column of buffered silica gel allows the separation of the compounds I and II which are finally isolated at their hydrochlorides and transformed, in case, into their doxorubicin analogues via their 14-bromo derivatives and subsequent hydrolysis with aqueous sodium formate.</p> |
