Methyl Isobutyl Ketone → HCID 11073868, compound

Participants

Reaction Conditions

Reaction Steps

10.6 g (content 94.3%, 5.75 mmol) of a racemate of 2-methyl-6-oxoheptanoic acid methyl ester and 20.0 g of MTBE were suspended in 50.0 g of 0.1 M phosphoric acid buffered solution (pH 7.0). The suspension was cooled to 10° C., then, 2.0 g (moisture percentage 56%, enzymatic activity 4028 KU/Kg, reduced by dry product) of immobilized Aspergillus flavus ATCC11492 strain-derived esterase (prepared by a method described in JP-A No. 2003-70471) was added, and the mixture was stirred at 10° C. for 51 hours while maintaining pH at 7.0 to 7.5 by appropriately adding 4% NaOH aqueous solution. Thereafter, the reaction solution was filtrated using Radiolite (filtration aid, trade name: manufactured by Showa Chemical Industry Co., Ltd.), to remove the esterase. The resultant filtrate was extracted twice with 25 g and 12.5 g of methyl isobutyl ketone (MIBK), then, the resultant organic layers were combined and washed with 15% saline, to obtain a MIBK solution of optically active (S)-2-methyl-6-oxoheptanoic acid methyl ester (optical purity 98.9% ee, yield 41.5%). The optical purity was analyzed by HPLC [Chiralpak AS-H, 4.6 mm×25 cm (manufactured by Daicel Chemical Industries, Ltd.)] like in Example 1.

Provenance & Evidence