| 摘要 |
PROBLEM TO BE SOLVED: To obtain the subject new compounds each exhibiting an antiferrodielectric liquid crystal phase at room temperature, easy in a switching operation at room temperature, and useful as a precursor for antiferrodielectric liquid crystal compounds used as raw materials for large face plate liquid crystal displays. SOLUTION: A compound of formula I (m is 3-6), or a compound of formula II. For example, syn-(2S,3R)-2-(4-hydroxybenzoyloxy)-7-ethoxy-3-methoxy-1,1,1- trifluoroheptane, and anti-(2S,3S)-2-(4hydroxybenzoyloxy)-7-ethoxy-3-methoxy-1,1,1- trifluoroheptane. The compounds of formulas I and II are obtained by reducing a compound of formula III with a metal hydride in an organic solvent, reacting the reaction product with methyl iodide, reducing the obtained O-methylated derivative with hydrogen in the presence of palladium-carbon catalyst in a solvent, and subsequently separating the obtained diastereomers from each other by means of silica gel chromatography. |
