Methyl chloroformate → Dimethyl cyclopentane-1,1-dicarboxylate

Participants

Reaction Steps

A solution of methyl cyclopentanecarboxylic acid (7.1 g, 38.16 mmol) in THF (14 mL) was added dropwise to a solution of lithium diisopropylamine (6.62 g, 61.2 mmol) in THF (55 mL) at −78° C. After stirring for 1 h at the same temperature, a solution of methylchloroformate (5.78 g, 61.2 mmol) in THF (14 mL) was added slowly and the mixture was allowed to warm to room temperature. After 18 h the reaction mixture was quenched with saturated aqueous NH4Cl solution (100 mL). THF was removed in vacuo and the aqueous residue was extracted with dichloromethane (100 mL×3). The combined organic layers were dried (MgSO4). After removal of the solvent under reduced pressure, purification by flash column chromatography using an eluting system of hexane/EtOAc (95:5) yielded the title compound as a clear colorless liquid (7.1 g, 93%). MH+187.

Provenance & Evidence