PREPARATION AND CRYSTAL-STRUCTURE OF (+ -)-1,2-BIS(3,4-DIMETHOXYPHENYL)-1,2-ETHANEDIOL/

(+/-)-1,2-Bis(3,4-dimethoxyphenyl)-1,2-ethanediol has been prepared by reduction of veratraldehyde with low-valent titanium. Reduction with TiCl4/Zn gave a mixture of the (+/-)-form (80 %) and the meso form (20 %) while only traces of the meso form could be detected when titanoce ne dichloride/Zn was used as the reducing agent. A combination of frac tionation on the basis of solubility properties and ion-exchange chrom atography on an anion exchanger using a borate solution as the eluent was used for the separation of the diastereomers. The crystal structur e of (+/-)-1 2-bis(3,4-dimethoxyphenyl)-1,2-ethanediol was determined by single-crystal X-ray diffraction methods. The compound crystallizes as colourless, hexagonal prisms in the hexagonal space group P6(2) [ as the (+)- or (-)-form ] with a = 12.309(5), c = 9.665(2) angstrom, V = 1268.1(9) angstrom3 and Z = 3. A total of 1229 unique reflections w as collected. Of these 893 were considered observed [I > 3sigma(I)] le ading to a final R-value of 0.033. The molecules are held together by van der Waals forces and moderately strong hydrogen bonds.