Kinetic Resolution of ( + )-2-Arylcyclohexanols Using Lipase AK and the Use of (-)-2-Arylcyclohexanols as Chiral Auxilaries in the Asymmetric Alkylation of a-Cyano Esters.

• Main Authors: Chen-Fan Wu, 吳晨帆
• Other Authors: Hsing-Jang Liu
• Format: Others
• Language: zh-TW
• Published: 2003
• Online Access: http://ndltd.ncl.edu.tw/handle/53239498227242727475

碩士 === 國立清華大學 === 化學系 === 91 === Abstract In this thesis, we like to discuss the efficient utility of the enzyme lipase AK to separate the optical antipodes (-)-2-and (+)-2-(1-naphthyl)cyclohexan-1-ol from its racemic mixture. By varying the reaction condition, the best experimental condition appeared to be the enzyme to alcohol ratio 2 : 1（by weight） and we use HPLC as the tool to separate it and after separation we duly analysed the result so obtained. In a typical procedure, the racemic alcohol and vinyl acetate were taken in the ratio of 10 : 1（by mole） and to this mixture was added the enzyme, lipase AK in t-BuOMe at 35℃, and the resulting mixture was stirred for 5 days. Taking optically pure alcohol as the chiral auxiliary, we also carried out the C-alkylation reaction of a-cyano ester and like to see the enantioselectivity, we also like to see the stereoselectivity outcome of a reaction by changing the aromatic part of the chiral auxiliary and also changing the reaction condition viz-temperature. In this context, we like to mention that when alkylation reaction was carried out with larger alkylating agent like benzyl bromide, we got higher diastereoselectivity 2 : 1. The detailed will be explained in this thesis.