Cyclopentanecarboxylic acid, 1-methyl-2-oxo-, methyl ester → 3-Methyl-2-oxocyclopentanecarboxylic acid methyl ester

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Reaction Steps

Methyl 1-methyl-2-oxocyclopentanecarboxylate (61.0 g, 0.39 mol) was added dropwise to a freshly prepared solution of NaOMe (0.78 mol) in MeOH (1 L) at ambient temperature. The solution was heated under reflux for 3 h and then concentrated. The residue was dissolved in toluene (1 L) and the resulting solution was heated under reflux for 5 h. The mixture was cooled to ambient temperature, washed with saturated aqueous NaHCO3 (500 mL×3) and brine (300 mL×1), dried over anhydrous sodium sulfate, and concentrated to dryness. The residue was purified by distillation to afford methyl 3-methyl-2-oxocyclopentanecarboxylate (39.0 g, 64% yield).

Provenance & Evidence