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Kinetic resolutions of cyclic racemic secondary alcohols (2-methylenecyclopentan-1-ol rac - 1a , 2-methylenecyclohexan-1-ol rac - 1b , 2-methylenecycloheptan-1-ol rac - 1c , 6-methylene-[1,3]dioxepan-5-ol rac - 1d , 2,2-dimethyl-6-methylene-[1,3]dioxepan-5-ol rac - 1e and trans -2-bromocyclohexan-1-ol rac - 3 ) catalyzed by different (commercial and in-house-made) lipases were performed using vinyl acetate in THF-hexane. In the most typical cases ( rac - 1b , rac - 1d and rac - 3 ), the immobilized Candida antarctica lipase B (CaLB, for rac - 1b and rac - 3 )- or sol–gel immobilized Pseudomonas fluorescens lipase (sol–gel LAK, for rac - 1d )-catalyzed batch mode reactions were compared to the continuous mode reactions carried out in an enzyme-filled stainless steel bioreactor. The effect of temperature (20–60 °C) and flow rate (0.1–0.3 ml min −1 ) on the continuous-flow acetylation of rac - 1b , rac - 1d and rac - 3 were investigated. In the kinetic resolutions of rac - 1b , rac - 1d and rac - 3 , the enantiomeric selectivities ( E ) were similar in the continuous-flow and batch (shake flask) modes. However, the productivities (specific reaction rate: r ), were significantly higher in the continuous-flow mode biotransformations of rac - 1b , rac - 1d and rac - 3 . |
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