The Establishment and Application of Simple Catalytic Preparation of High Optical Active Chiral Compounds

The reaction of aldehydes with diketene is known to give 5-hdroxy-3-ketoesters by Lewis acid cat·like TiCl·D24·D2。但该反应中的产品是分离混合物，而与二酮没有给予添加产品的Cinnamic Aldehyde的反应。作者obtained the products in high y？using Ti（OiPr）。此外，我们还发现了由chiral schiff base-titanium复合体催化的上有效反应，该复合体对三甲基氰化物的不对称反应非常有效。在这种反应中，某些光学活性的产品成为合成药物的前饱和剂，对低胆固醇具有特别活性。优化研究的结果影响了反应条件提供90%的ee的产品在良好的yield。Also in the use of 20 mol% of the chiral catalist gave the product in good enantio-selectivity only in use of an equimolar amount of Ti（OiPr）-D24-D2。Chiral催化剂的恢复是由cationic resins完成的，而Dowex则是由Ube化学研究所的研究重新出版的。

The reaction of aldehydes with diketene is known to give 5-hdroxy-3-ketoesters by Lewis acid catalyst like TiClィイD24ィエD2. But the products in this reaction are racemic mixture and the reaction of cinnamic aldehyde with diketene did not give addition product. The author obtained the products in high yield using Ti(OiPr)ィイD24ィエD2 as catalyst. Also we found the above enantioselective reaction catalyzed by chiral schiff base-titanium complexes which were very effective for the asymmetric reaction of aldehydes with trimethylsilyl cyanide. In this reaction the some optically active product become precursor of synthetic drugs, particularly active for lowering cholesterol. The results of optimization research afforded the reaction conditions giving 90% ee's product in good yield. Also in the use of 20 mol% of the chiral catalist gave the product in good enantio-selectivity only in use of an equimolar amount of Ti(OiPr)ィイD24ィエD2. The recovery of the chiral catalyst was accomplished by cationic resins such as Dowex which was revailed by the research in Ube Chemical Institute.