Molecular structure of nordihydroguaiaretic acid

Abstract

The structure and stereochemistry of nordihydroguaiaretic acid has been confirmed by the single-crystal X-ray analysis of a heavy-atom derivative. The crystals of 2,3-di-(2-bromo-4,5-dimethoxybenzyl)butane are monoclinic, space group P2/c, with a= 16·92, b= 4·81, c= 13·91 Å, and β= 93° 55′, and Z= 2. The structure was determined from photographic data and has been refined to an R-factor of 0·11 on 1586 independent reflexions. The molecule has a centre of inversion and exists as the meso-form. Some effects due to intramolecular steric influences are described.