Preparation and Lipase-catalyzed Optical Resolution of 2,2,2-Trifluoro-1-(naphthyl) ethanols
作者:Katsuya Kato、Masato Katayama、Rakesh K. Gautam、Shozo Fujii、Hiroshi Kimoto
DOI:10.1271/bbb.59.271
日期:1995.1
The optical resolution of racemic 2,2,2-trifluoro-1-(naphthyl)ethanols (TFNEs) was achieved by lipase-catalyzed enantioselective acetylation with vinyl acetate in octane, S-acetates and R-alcohols being obtained. The introduction of a methyl group into the naphthalene ring at the 4-position (2b) or the 2-position (2c) markedly decreased the reactivity, in particular for 2c. 2,2,2-Trifluoro-1-(1-naphthyl)ethanol (2a) behaved differently from the regio-isomer, 2,2,2-trifluoro-1-(2-naphthyl)ethanol (2d): The enantioselectivity of lipases [LIP (Pseudomonas), PLC (Alcaligenes), and ALC (Achromobacter)] was high for 2a but low for 2d, whereas lipases [AK and PS (Pseudomonas)] exhibited higher selectivity for 2d than for 2a. Three other derivatives, 2,2,2-trifluoro-1-(phenyl)ethanol (2e), 2,2,2-trifluoro-1-(indol-3-yl)ethanol (2f), and 1-(1-naphthyl)ethanol (2g), were prepared, and their behaviors with respect to lipase-catalyzed acetylation were compared with 2a.
对消旋体
2,2,2-三
氟-1-(
萘基)
乙醇(TFNEs)的光学分辨率是通过在
正庚烷中用
脂肪酶催化的对映选择性
醋酸化实现的,得到S-
醋酸酯和R-醇。将
甲基引入
萘环的4位(2b)或2位(2c)显著降低了反应活性,特别是对于2c。
2,2,2-三
氟-1-(1-
萘基)
乙醇(2a)与其区域异构体
2,2,2-三
氟-1-(2-
萘基)
乙醇(2d)表现出不同的行为:
脂肪酶[LIP(假单胞菌)、PLC(阿尔卡利菌)和ALC(嗜色菌)]对2a的对映选择性较高,但对2d较低,而
脂肪酶[AK和
PS(假单胞菌)]对2d的选择性高于对2a。还合成了另外三个衍
生物,
2,2,2-三
氟-1-(
苯基)
乙醇(2e)、
2,2,2-三
氟-1-(
吲哚-3-基)
乙醇(2f)和1-(1-
萘基)
乙醇(2g),并将它们在
脂肪酶催化的
醋酸化中的表现与2a进行了比较。