A new 4-substituted-2-cyclohexenone synthesis

Article abstract of DOI:10.1016/S0040-4039(00)79311-7

Conjugate addition of a variety of Grignard reagents to 2-cyclopentenone followed by cyclopropanation of the resulting enol ethers gave a range of substituted cyclopropyl silyl ethers in good yield. Treatment of these cyclopropyl silyl ethers with ferric chloride in DMF gave the one carbon ring expanded β-chloro ketones which were eliminated to the corresponding 4-substituted-2-cyclohexenones.