Anomalies in the asymmetric transfer hydrogenation of several polycyclic meso compounds

Over the course of developing a multigram scale preparation of epoxy quinol 1 via asymmetric transfer hydrogenation (ATH) using the Noyori Ru(arene)(S,S-TsDPEN) catalysts, we observed several unexpected phenomena, including (i) chemoselective alkene versus ketone reduction of an enedione, (ii) a significant arene ligand effect (p-cymene vs mesitylene) on the reaction pathway, and (iii) solvent-based reversal of the sense of enantioinduction.