Sulfuric Acid → HCID 13717262, compound

Participants

Reaction Steps

Methylmagnesium iodide (0.22 mole) in ether (200 ml.) was added dropwise to a solution of 2-isopropyl-2-carbethoxycyclopentanone (40 g, 0.2 mole) in ether (150 ml.), and the mixture was heated under reflux for 17 hours. Dilute sulphuric acid was then added and the ether layer was separated and dried (MgSO4). The ether was removed to leave 2-carbethoxy-1-methyl-2-isopropylcyclopentanol. This compound was dissolved in pyridine (200 ml.) and cooled to -10° C. Thionyl chloride (25 ml.) was then added keeping the temperature at -5° C. After 2 hours at -5° C., ether (500 ml) and an excess of 2N sulphuric acid were added and the organic layer was separated. The aqueous layer was extracted with ether and the combined extracts were dried (MgSO4). The solvent was removed and the residue was distilled to give 1-carbethoxy-1-isopropyl-2-methylcyclopent-2-ene, bp. 107°-110°/17 mm.

Provenance & Evidence