Synthesis and absolute configuration of (1 S,8 S)- as-hydrindacene-1,8-diol as determined by the circular dichroism exciton chirality method

Abstract

2,3,6,7-Tetrahydro- as-indacene-1,8-dione 4 was prepared in 4 steps starting from 2-methyl-furan by modification of a literature procedure. Appliance of Noyori’s asymmetric transfer hydrogenation, resulted in (1 S,8 S)-1,2,3,6,7,8-hexahydro- as-indacene-1,8-diol 5 in high yield (81%) and excellent enantioselectivity (>99% ee) or (8 S)-8-hydroxy-3,6,7,8-tetrahydro-2 H- as-indacen-1-one 6 in moderate yield (58%) and equally high enantioselectivity (98.5% ee), depending on the conditions. The asymmetric reduction was expected to yield the ( S)-alcohols using the ( S, S)-Ts-DPEN ligand, which was confirmed by the appliance of the exciton chirality method on the corresponding bis( p-dimethylamino)benzoate 7 .