Marchantin M trimethyl ether

The title macrocycle, C31H30O5, is comprised of two bibenzyl ether moieties linked cyclically by spacers which each consist of two-carbon alkyl chains . The observed conformation of the macrocycle may be partly stabilized by i ntramolecular CD H . . .O close contacts. The packing appears to be directe d by van der Waals forces. This work explains the occurrence of a signal fo und in the H-1 NMR spectra of both marchantinquinone and marchantin M trime thyl ether at delta = 5.49 and 5.56 p.p.m., respectively. The shift in the position of the expected peak can be explained by the proximity of an H ato m belonging to one of the aromatic rings to another ring in the same molecu le.