Yoshio Tanaka, Takayoshi Chiyo, S. Iijima
Oct 1, 1983
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Influential Citations
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Journal
Molecular Crystals and Liquid Crystals
Abstract
Abstract Asymmetric decarboxylation of 2-ethyl-2-(4-methylphenyl)-propane-1,3-dioic acid was studied in some cholesteric liquid crystalline media such as 2,4-hexadienoic, benzoic, 2,4-dichlorobenzoic, and trans-cinnamic acids at 158–163°C, and compared with the solution reaction in bomyl acetate. Several experiments were conducted as described by Verbit, et al., or with various changes in the procedures, but all invariably afforded low optical active 2-(4-methylphenyl)butanoic acid in high chemical yields. This is also confirmed by chiral recognition through diastereomeric complex formation with optical active shift reagent in 1H NMR spectroscopy. This decarboxylation, thus, should not clearly demonstrate the ability of the chiral mesophase to induce appreciable asymmetric reaction: The solvent order or macroscopic helical structure formed by cholesteric liquid crystals appears to play little role in determining the stereochemical course of this decarboxylation.