A new stereocontrolled entry into the anthracyclinone families. Part 1: Synthesis of bicyclic precursors of 4-demethoxy-7-deoxy-derivatives

Stereocontrolled Reactions Mediated by a Remote Sulfoxide Group: Synthesis of Optically Pure anti-β-Amino Alcohols

“…However, the use of the OTIPS derivative can be more convenient in some cases in order to avoid epimerization 22 of the final benzylic alcohol, as was reported in some cases. 23 In summary, the reaction between prochiral oxygenated 2-p-tolylsulfinylbenzyl carbanions with N-sulfinylimines allows formation of the C-C bond to proceed with complete stereoselective control at the two new stereogenic centers. The method allows for a one-step synthesis of enantiomerically pure 1,2-diaryl anti-1,2-amino alcohols with identical or different aromatic residues and 1-aryl-2-alkyl anti-1,2amino alcohol derivatives.…”

“…Hydrogenolysis of the C−S bond with Ra−Ni proceeds in higher yield with substrates containing a free hydroxyl group. However, the use of the OTIPS derivative can be more convenient in some cases in order to avoid epimerization of the final benzylic alcohol, as was reported in some cases 3 …”

Approaches to the stereocontolled synthesis of anthracyclinones: Preparation of optically pure bicyclic intermediates for the regioselective construction of the tetracyclic skeleton

“…Anodic oxidation of hydroquinones 1a-d 6,7 was performed at 0 ºC using the pair Pt (anode) / Cu (cathode) in methanolic KOH (2%) and 100 mA (direct current). 16 The bis-ketals 11a-d were obtained as dark oils with yields ranging between 50% and 97%, with the best results obtained for tertiary alcohol derivatives.…”

“…3 The two main problems of the different strategies used for synthesizing anthracyclinones are related to the stereoselective construction of the A ring containing the chiral center, 4 and the regioselective preparation of the tetracyclic skeletons from bicyclic fragments. 5 In the first context we have reported a versatile method based on the use of the sulfinyl group as a chiral auxiliary for creating the tertiary carbinol in high enantiomeric excess, 6 and for achieving the intramolecular asymmetric Pummerer reaction affording the bicyclic precursors of the anthracyclinones 1 (Scheme 1). …”

Design, Synthesis, and Evaluation of α‐(Hydroxymethyl)cycloalkanols

“… [70–73] All the three compounds were supposed to be retrosynthetically derived from cyanohydrins of the corresponding 4‐substituted cyclohexanones. The enzymatic‐catalyzed chemical addition of HCN to 47 was performed under optimized conditions using (S)‐MeHNL with high cis selectivity [74–76] . The cyanohydrin 48 was obtained almost quantitatively in a cis / trans ratio of 96 : 4.…”