Sodium Hydroxide → (2S,3R)-2,3-epoxy-3-cyclohexylpropionic acid

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Reaction Steps

500 ml of toluene containing 100 g of racemic methyl 2,3-epoxy-3-cyclohexylpropionate, was added to 500 ml of a 1M tris-HCl buffer solution (pH 8.0) containing lipase type VII (derived from Candida rugosa, prepared by Sigma Co., U.S.A.) in a concentration of 5 g/l, and asymmetric hydrolysis reaction was carried out at 30° C. for 48 hours at a stirring speed of 600 rpm. After the reaction, a 1N sodium hydroxide aqueous solution was added to the reaction solution to adjust the pH of the aqueous phase to 10, whereupon the aqueous phase was separated. The aqueous phase was then adjusted to pH 2 with a 1N hydrochloric acid solution and then extracted twice with 300 ml of t-butyl methyl ether, and the organic layer was concentrated under reduced pressure to obtain 38.5 g of (2S,3R)-2,3-epoxy-3-cyclohexylpropionic acid as crude crystals. The crude crystals were dissolved in 200 ml of a solution of toluene/n-heptane=1/2 (v/v) and heated and dissolved for 20 minutes with stirring at 60° C. The solution was gradually cooled from 60° C. to 20° C. and then cooled with ice for 30 minutes, whereupon precipitated crystals were collected by filtration to obtain 34.2 g of crystals of (2S,3R)-2,3-epoxy-3-cyclohexylpropionic acid (99.1% ee [α]D20 =+20.8 (c 1.04, CHCl3)).

Provenance & Evidence