Dearomatizing annelation of five-membered rings to naphthalenes by organolithium cyclization

[GRAPHICS] gamma-Lithiopropylnaphthalenes and their oxa- and aza-tethered analogues cyclize by nucleophilic addition of the organolithium to the naphthalene ring. The resulting benzyllithiums react stereoselectively with electrophiles to give dearomatized tricyclic products with structural similarity to the aryinaphthalene lignans.