Synthesis and Resolution of Substituted [5]Carbohelicenes

摘要

Three types of racemic [5]helicenyl acetates (la, 2, and 3a) were synthesized. The synthesis of 2 was achieved by regioselective oxidation using o-iodoxybenzoic acid. The enzymatic kinetic resolution of la-3a was studied. The conversion with the highest rate and ee was obtained using la as the substrate and lipase Amano PS-IM as the enzyme. The two enantiomers of 1-[5]helicenol 3b were separated using (1S)-10-camphorsulfonyl chloride as the chiral resolving agent.