Enantiomerentrennung, Circulardichroismus, Racemisierung und Röntgenstrukturanalyse des Benzo[2.2]metacyclophans

Abstract

The title compound 1 was separated into the enantiomers by chromatography on cellulose triacetate: (–)-1 exhibits an enantiomeric purity of 100% with [α]36520 = −3210 ± 135 (acetone). A racemization barrier ΔG≠ = 125 kJ/mol is found by means of a kinetic study. The helicity of the molecule is demonstrated through these results as well as through an X-ray analysis, which is also described.