Synthetic Transformations of Higher Terpenoids:XVIII.* Synthesis of Optically Active 9,10-Anthraquinone Derivatives

摘要

Retro-Diels-Alder decomposition of dodecahydro-endo-4b,]2-ethenochrysene-1,4-diones obtained from a tricyclic diterpenoid,levopimaric acid,gave optically active 5-[2-(6-vinyl-2,6-dimethyl-2-carboxycyclo-hexyl)ethyl]-7-isopropyl-1,4-naphthoquinones which reacted with silyloxybutadienes to produce the corresponding 6-and 7-hydroxyanthraquinones,5-furyl-7-hydroxytetrahydroanthraquinones,or 5-furyl-7-oxohexa-hydroanthraquinones.Condensation of the naphthoquinone derivatives with 5-isopropenyl-2,3-dihydrothio-phene 1,1-dioxide resulted in the formation of 6,11-dioxodihydro-and 6,ll-dioxohexahydroanthra[2,1-6]thio-phene 3,3-dioxides.6-and 7-Hydroxyanthraquinones were also obtained by reaction of dodecahydro-endo-4b,12-ethenochrysene-1,4-diones with Danishevsky diene,followed by cleavage of the polycyclic adducts.The cycloaddition of 5-[2-(-2-carboxy-2,6-dimethyl-6-vinylcyclohexyl)ethyl]-7-isopropyl-1,4-naphthoquinones in the presence of Lewis acids was characterized by increased regioselectivity.