Total synthesis of the novel, biologically active epoxyquinone dimer (+/-)-torreyanic acid: a biomimetic approach.

[reaction: see text] A total synthesis of the complex, biologically active, dimeric natural product (+/-)-torreyanic acid, which is composed of seven rings and laced with dense, variegated oxy-functionalization, has been accomplished from readily available allyl-substituted p-benzoquinone 8. Our synthetic stratagem involves crafting an epoxyquinone monomer for use in a biomimetic cascade process involving tandem a 6pi electrocyclization and a Diels-Alder dimerization.