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Abstract

4-substituted anthracyclinones of general formula (I): ##STR1## wherein R represents a hydrogen atom or a COOR.sub.1 group in which R.sub.1 may be a hydrogen atom or an optionally substituted C.sub.1 -C.sub.10 alkyl group, which are intermediates in the preparation of antitumor anthracycline glycosides, are prepared by: (i)(a) reacting a 4-demethyl-4-sulfonyl-7-deoxy-13-dioxolanyl daunomycinone of formula (V): ##STR2## wherein R' represents an alkyl group having from 1 to 10 carbon atoms optionally substituted by one or more halogen atoms or an aryl group optionally substituted by halogen, alkyl, alkoxy or nitro, in a reducing environment with a catalytic amount of a compound of formula (VIII): ML.sub.n L'.sub.m wherein M represents a transition metal atom, L and L', which may be the same or different, each represent an anion or a neutral molecule and n and m may vary from 0 to 4, such as to obtain a compound of formula (VII): ##STR3## wherein R represents hydrogen; or (b) carbonylating a 4-demethyl-4-sulfonyl-7-deoxy-13-dioxolanyl daunomycinone of formula (V) as defined above, with carbon monoxide in the presence of a nucleophile R.sub.1 OH wherein R.sub.1 is as defined above, an organic or inorganic base and as catalyst a compound of formula (VIII) as defined above, such as to obtain a compound of formula (VII) as shown above wherein R represents a COOR.sub.1 group; and (ii) introducing an .alpha.-hydroxy group at the 7-position and removing the 13-oxo protecting group by acid hydrolysis from the resultant compound of formula (VII).

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First Claim