Diisopropylamine → (2R,3R)-2-butyl-3-hydroxyoctanoic acid t-butyl ester

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Reaction Conditions

Reaction Steps

A dried two-necked flask was cooled to −78° C., after which diisopropylamine (5.41 g, 53.5 mmol) was introduced thereto. Then, methyllithium (a 0.98M diethyl ether solution, 45 ml, 44.1 mmol) was added dropwise thereto, and stirred for 10 minutes. The resulting mixture was heated to 0° C., and stirred for another 30 minutes. The reaction solution was cooled to −48° C., the (R)-3-hydroxyoctanoic acid t-butyl ester (3.50 g, 16.2 mmol) obtained in Production Example B-1 was added dropwise thereto, and then the mixture was stirred for 30 minutes. To the obtained mixture was added hexamethylphosphoric triamide (HMPA) (7 ml), the mixture was stirred for one minute, then 1-iodobutane (3.87 g, 21.0 mmol) was added dropwise thereto. After the reaction solution was stirred at −48° C. for one hour, a saturated ammonium chloride solution was added thereto, and extracted 3 times with diethyl ether. The resulting organic layer was dried with anhydrous magnesium sulfate, filtered, and condensed. The obtained residue was purified by column chromatography (silica gel: 150 g, n-hexane/ethyl acetate=15/1) to produce the target compound (1.98 g, 44%).

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