Methyl acetoacetate → 3-[(Acetyl) (methoxycarbonyl)methyl]cyclopentanone

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Reaction Conditions

Reaction Steps

Under an atmosphere of argon, 12.6 mg (0.02 mmol, S/C=50) of Ru[(S,S)-Tsdpen] (hexamethylbenzene), 84 μL (1.0 mmol) of 2-cyclopentenone, 108 μL (1.0 mmol) of methyl acetoacetate, and 1 mL of 2-methyl-2-propanol were placed in a 20 mL Schlenk tube and stirred at 40° C. for 24 hours. This solution was purified by flash column chromatography (hexane/acetone=90/10, SiO2) to give 196 mg (99% yield) of the title compound. The percentage diastereomeric excess and the percentage enantiomeric excess were measured by 1H NMR and HPLC (CHIRALPAK AS manufactured by Daicel Chemical Industries, Ltd., hexane:2-propanol=80:20, flow rate 1.0 mL/min, detection at 210 nm), it was found that the product was a 1:1 diastereomeric mixture and each diastereomer was present in 70% ee.

Provenance & Evidence