Chiral Recognition of Alcohols in the Crystal Lattice of Simple Metal Complexes Ofo,o′-Dibenzoyltartaric Acid: Enantiocomplementarity and Simultaneous Resolution

A simple preparative method for the enantiomeric enrichment of alcohols is reported. Crystallization of the complexes of alcohols formed with calcium and zinc O,O'-dibenzoyltartrates led to effective resolutions of the alcohols. However, zinc and calcium dibenzoyltartrates are complementary resolving agents upon coordinative resolution of less-hindered alkoxy alcohols. Mixed copper(II) salts of O,O'-dibenzoyltartaric acid formed with carboxylic acids can also be applied to the resolution of alkoxy alcohols, thereby providing the simultaneous resolution of an alcohol and a carboxylic acid. Zinc dibenzoyltartrate can form coordination compounds with alkoxy alcohols as well as lattice inclusion compounds with simple alcohols as revealed by the four X-ray structures reported here.