Nuclear alkylation of 1,4-diaminoanthraquinone. Synthesis of chiral 6,11-diaminoanthracyclinones related to ametantrone from carbohydrates

1,4-Diaminoanthraquinone [leuco derivative (4)] with aldehydes in the presence of 1,8-diazabicyclo[5.4.0]undec-7-ene in dimethyl formamide afforded (after aerial oxidation) 2-(hydroxyalkyl)-1,4-diaminoanthraquinones in good yields; reaction of (4) with 1,2-O-isopropylidene-3-O-methyl-a-D- xylopentodialdo-1,4-furanose (8) gave, stereospecifically, the hydroxyglycityl derivative (9) which was readily transformed into the novel 6,11- diaminoanthracyclinone (12).