Ethyl 4-oxocyclohexanecarboxylate → Ethyl 4-methylidenecyclohexane-1-carboxylate

Participants

Reaction Steps

Lithium bis(trimethylsilyl)amide (1.0 M in THF, 15 mL, 15 mmol) was added dropwisely to a stirred solution of methyltriphenylphosphonium bromide (5.36 g, 15 mmol) in THF (50 mL) at 0° C. and stirred for 40 min at the same temperature. A solution of ethyl 4-oxocyclohexanecarboxylate (2.04 g, 12 mmol) in THF (20 mL) was added slowly at 0° C. and stirred for 2 h from 0° C. to room temperature. The reaction was quenched with saturated NH4Cl aq. and extracted with hexane. The collected organic layer was dried over MgSO4 and concentrated under reduced pressure. The solvent (100 mL, hexane/Et2O=5/1) was added to the residue and stirred for 30 min. The suspension was filtrated. The filtrate was concentrated under reduced pressure. The residue was purified by silicagel chromatography (5% EtOAc/hexane as eluent) to provide compound A122-1 (1.478 g, 73%) as a colorless oil.

Provenance & Evidence