Russell, R.A.Irvine, R.W.Warrener, R.N.2014-10-262014-10-261986Journal of Organic Chemistry, 1986; 51(9):1595-15990022-32631520-6904http://hdl.handle.net/2440/8666113-Dihydrodaunomycin 1 has long been recognized as the major human metabolite of the antineoplastic anthracycline daunomycin 2.¹ Whilst 1 has been prepared by microbial² and chemical reduction³of 2, no attempt to assign the stereochemistry at C13⁴ has been reported. Recently Cassinelli et al. have reported⁵that 4-demeth-oxydaunomycin 3 (idarubicin) can be reduced microbially to afford an idarubicinol 4 identical with that excreted by patients treated with 3. These authors initially assigned the 13R stereochemistry to this product, although this was subsequently corrected by Broadhurst et al.,⁶ who showed that the totally synthetic 13S isomer corresponded to the biologically obtained product. As both dihydroderivatives 1 and 4 are active antineoplastic agents,²^,7routes leading to their total synthesis are of considerable interest. In addition another dihydro compound, namely 7-deoxy-13-dihydrodaunomycinone 5, has reportedly been isolated from a strain of Streptomyces (PD.J566) originating from Michaelmas Cay in Australia.⁸ Since this product occurred together with known daunomycin derivatives, it was assumed to have the 9R configuration. However, subsequent attempts to synthesize 5 stereospecifically by borohydride reduction of (−)-7-deoxydaunomycinone yielded unseparated mixtures of the9R,13R and 9R,13S isomers.⁹ Consequently, the configuration of C13 of the natural product remained undefined. © 1986, American Chemical Society. All rights reserved.en© 1986 American Chemical SocietyJournal article003000926210.1021/jo00359a0412-s2.0-0022492025102289