A formal homo-Nazarov cyclization of enantioenriched donor-acceptor cyclopropanes and following transformations: asymmetric synthesis of multi-substituted dihydronaphthalenes.

Multi-substituted trans-dihydronaphthalenes were obtained in high enantiomeric excess from a TiCl4-mediated cyclization of enantioenriched donor-acceptor cyclopropanes, followed by a triflation of the hydroxy groups. The C-OTf bond in these multi-substituted trans-dihydronaphthalenes is susceptible to further Pd-catalyzed hydrogenations and coupling reactions, which afforded the corresponding C-H or C-C bonded products.