The 1: 1 complex of o, o′-dichloro-R-BINOL and SbCl5 initiates the enantioselective cationic polycyclization of polyunsaturated substrates at a predictable π-bond which may be either terminal or, as shown herein, internal. The extension of this powerful construction to internal π-bonds expands the scope of this method and opens up very short pathways to numerous chiral polycyclic molecules, including natural products and their analogues. ...
