Absolute configuration determination of donor–acceptor [2.2]paracyclophanes by comparison of theoretical and experimental vibrational circular dichroism spectra

Vibrational circular dichroism (VCD) spectra were obtained for the assignments of the absolute configurations of diastereomeric 4,7‐bis(methoxycarbonyl)‐12,15‐dimethoxy‐[2.2]paracyclophanes (1 and 2), and density functional theory (DFT) calculations were performed at the B3LYP/6‐31G(d) level for all possible conformations of both 1 and 2 to give the theoretical VCD spectra. Comparisons of the experimental and theoretical VCD spectra obtained unambiguously established the absolute configurations of the dextrorotatory (+)‐enantiomers as (4Sp;12Sp)‐1 and (4Sp;12Rp)‐2, respectively. © 2006 Wiley‐Liss, Inc. Chirality