新規光学活性カルボン酸の調製とらせん誘起剤への利用 Preparation of Novel Optically Active Carboxylic Acids and Application as Chiral Dopants for Nematic Liquid Crystals
Chiral 2-phenylpropanoic acid derivatives and 2-methylchroman-2-carboxylic acid derivatives were prepared as new chiral dopants for nematic liquid crystals. The optically active (<I>S</I>) -2- (4-butylphenyl) propanoic acid was prepared from (<I>S</I>) -2-propanoic acid chloride and butylbenzene using an analogous method employed for the synthesis of ibuprofen. Their helical twisting power (HTP) was determined and the relationship with their functional groups and flexible terminal structures was studied. (<I>S</I>) -1- [4- (<I>trans</I>-4-Butylcyclohexyl) phenyl] -2-phenylpropane-1-one showed a large HTP value 20.4 μm<SUP>-1</SUP> (MHTP = 5.50 μ<SUP>-1</SUP>mol<SUP>-1</SUP>kg).<BR>The HTP was also studied for 2-methylchroman-2-carboxylic acid derivatives having a chiral center in the cyclic structure. The starting material, 6-benzyloxy-2-methylchroman-2-carboxylic acid, was prepared and resolved by a diastereomeric salt formation method. Its ethyl ester showed a good HTP value 11.2 μm<SUP>-1</SUP> (MHTP = 3.65 μm<SUP>-1</SUP> mol<SUP>-1</SUP> kg) showing the rigid cyclic structure having a benzyl group at the 6-position was also effective for chiral induction.
- 有機合成化学協会誌 : JOURNAL OF Synthetic Organic Chemistry JAPAN
有機合成化学協会誌 : JOURNAL OF Synthetic Organic Chemistry JAPAN 64(10), 1032-1040, 2006-10-01
The Society of Synthetic Organic Chemistry, Japan