Enantiopure anthrylene-ethynylene cyclic tetramer and racemization via rotation of anthracene unit about acetylenic axes

Org Lett. 2008 Feb 7;10(3):417-20. doi: 10.1021/ol702783v. Epub 2007 Dec 29.

Abstract

Four anthracene and four acetylene units are used to construct a chiral pi-conjugate macrocycle, the chirality of which is due to the restricted rotation about acetylenic axes. Enantiomers were readily resolved by chiral HPLC and racemized slowly even at 70 degrees C.