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 C2. Both enantiomers of the new helically chiral hexacyclic system have been successfully separated using (R)-2-phthalimidopropanoic acid chloride as a chiral resolving agent.