Synthesis and resolution of a new thiahexahelicene

A new thiahexahelicene bearing a methoxy group, at a selected position on the terminal aromatic ring, was prepared in a good yield through Heck coupling and photocyclization reactions. The X-ray crystal structure of the product indicates that its conformation closely resembles that of the unsubstituted hexahelicene, whose idealized symmetry is C-2. Both enantiomers of the new helically chiral hexacyclic system have been successfully separated using (R)-2-phthalimidopropanoic acid chloride as a chiral resolving agent. (C) 2012 Elsevier Ltd. All rights reserved.