Synthesis and Chiroptical Properties of 5,7-Dioxobicyclooct-2-ene and Bicyclooctane-2,5-dione

Article abstract of DOI:10.1021/jo00350a019

5,7-Dioxobicyclo<2.2.2>oct-2-ene (5) and its dihydro derivative 9 were obtained in racemic from by sequential Diels-Alder addition of maleic anhydride to hydroquinone, hydrolysis of the adduct to diacid 7, oxidative decarboxylation of 7 with lead tetraacetete, and catalytic hydrogenation.Partial resolution of 7 with brucine or quinine afforded (-)-5 in 80-86percent enantiomeric purity.Katalization of (+/-)-5 with diethyl (R,R)-(+)-tartrate and subsequent chromatographic separation of the diastereomeric monoketals gave optically pure samples of both antipodes of the enedione.This substance was found to interact powerfully with plane and circularly polarized light.The Cotton effects observed in the ORD and CD spectra of (-)-5 indicate that its absolute configuration is 1S,4S when analyzed by the generalized octant rule.It follows that (-)-9, its hydrogenation product, is 1R,4R.