Enhanced stereoselectivity in photoelectrocyclization of tropolone ethers via confinement in chiral inductor-modified lyotropic liquid crystals

Abstract

Photochemistry of tropolone methyl ether ( 1) and optically pure ( S)-tropolone-2-methylbutyl ether ( 4) has been examined in lyotropic liquid crystals (LCs) in the presence of a chiral inductor. LCs significantly enhance the influence of chiral inductors during the photoelectrocyclization of the tropolone ethers. Chiral inductors that lead to 1:1 mixtures of enantiomers or diastereomers in solution give products in up to 40% enantiomeric excess for 1 and 35% diastereomeric excess for 4 in LCs.