CONFORMATIONAL BEHAVIOUR AND INCLUSION COMPOUND FORMING PROPERTIES OF 5,18-DISUBSTITUTED DERIVATIVES OF 5,11,12,18-TETRAHYDROTRIBENZODIAZACYCLODODECINE-6,17-DIONE

Article abstract of DOI:10.1016/S0040-4039(01)90504-0

An X-ray structure analysis shows that the 5,18-dimethyl derivative (5) of the title compound (4) crystallises from xylene as a 1:1 inclusion compound in which the host molecules adopt propeller-like conformations (7 and 7*) with almost perfect C₂ symmetry.Dynamic 1H n.m.r. spectroscopy shows that the 5,18-dibenzyl derivative (6) of (4) forms a 1:1 inclusion compound with ethanol in the solid state and undergoes ring inversion (7 <*> 7*) between enantiomeric propeller-like conformations in solution against a barrier of 21.1 kcal/mol.