SYNTHETIC ANTHRACYCLINONES-XXVII. ANTHRACYCLINONES BY INTRAMOLECULAR MARSCHALK REACTION. SYNTHESIS OF THE FEUDOMYCINONES AND RHODOMYCINONES.

Article abstract of DOI:10.1016/S0040-4020(01)91521-2

1,4,5-Trihydroxy-9,10-anthraquinone is transformed regioselectively to the α-hydroxy dichlorides 18-21, which are cyclized to yield predominantely the naturally configurated 9,10-trans-diols 1,3,26, and 27 (80 to 96percent d.e.).The monotrifluoroacetates 38-40 derived from the trans-diols are hydroxylated via bromination at C-7 to yield almost exclusively the 7,9-cis-9,10-trans-triols α₁-rhodomycinone (4), feudomycinone D (7), and 4-O-methyl-β-rhodomycinone (42).The feudomycinones A (5) and C (6) are obtained with less chemo- and stereoselectivity by hydroxylation of the 10-deoxycompounds 33 and 34.