Synthesis and Stereochemical Behavior of a New Chiral Oxa[7]heterohelicene

Abstract A new chiral oxa[7]heterohelicene 1b was synthesized by catalytic aerobic-oxidative tandem cyclization of the o-phenylene-linked bis(2-naphthol) derivative 3 with palladium acetate in dimethyl sulfoxide. Optical resolution of 1b was possible on chiral HPLC, but it was found stereochemically rather unstable at ambient temperature. Kinetic analysis and DFT calculation for the dynamics of racemization of 1b were also disclosed.