The Synthesis of enantiomerically pure novel liquid crystal compounds containing the bis(trifluoromethyl)alkanediol moiety.

手性1，1，1-三氟甲基-2-烷醇类铁电液晶化合物(AFCL)是一种重要的高速开关器件。Kusumoto和他的同事最近合成了独特的二聚体AFLC分子，其中包含光学活性的双(三氟甲基)烷基二醇作为手性核心单元。然而，已报道的制备光学纯的双(三氟甲基)烷二醇的方法需要在手性相上使用高效液相色谱来拆分。我们以前报道过南极假丝酵母脂肪酶催化外消旋1，1，1-三氟-2-烷醇的转酯化反应，具有很好的对映体选择性。更有效地实现了乙酸乙酯的水解性。接下来，我们尝试了以乙酸乙烯酯为酰基供体，在有机溶剂中进行二醇1的反式立体反应。然而，转酯反应并没有发生。幸运的是，(±)-1的水解反应顺利进行，为单乙酸酯和二醇提供了高效的对映选择性。报道了脂肪酶催化双(三氟甲基)烷二醇的水解反应。以该反应得到的光学活性双(三氟甲基)烷基二醇为原料，合成了新型的二聚型AFCL。

Ant ferroelectric liquid crystal compounds(AFCLs), which possess a chiral 1,1,1-trifluoromethyl-2-alkanol moiety, are known to be important high-speed switching devices. Kusumoto and his colleagues recently the synthesis of unique dimeric AFLCs molecules which contain optically active bis(trifluoromethyl)alkanediols as chiral core units. The reported means for preparing optically pure bis(trifluoromethyl)alkanediols, however, required a nuisance resolution process using HPLC on chiral phase. We previously reported that Candida antarctica lipase catalyzed trans-esterification of racemic 1,1,1-trifluoro-2-alkanols with perfect enantioselectivity. We also achieved the hydrolysis of acetate more effectively. We next attempted trans-sterification of diol 1 in organic solvent using vinyl acetate as an acyl donor. Trans-esterification, however, did not take place. Fortunately, hydrolysis reaction of (±)-1 proceeded smoothly to provide monoacetate and diol with efficient enantioselectivity. We report the results of lipase-catalyzed hydrolysis reaction of bis(trifluoromethyl)alkanediols. Using optically active bis(trifluormethyl)-alkanediols obtained in this reaction as starting materials, synthesis of novel dimer type AFCLs has been demonstrated.