Two methods for the preparation of 2-cyclohexenones from resin-bound 1,3-cyclohexanedione
作者:Mark E. Fraley、Robert S. Rubino
DOI:10.1016/s0040-4039(97)00631-x
日期:1997.5
The addition of organolithium or Grignard reagents to vinylogous ester resin 1 followed by mild hydrolysis of product resins 2 provides 3-alkyl-2-cyclohexenones in high purity (>95%). Alternatively, conversion of 1 to vinyl triflate resin 4 followed by palladium-mediated couplings with aryl boronic acids and hydrolysis furnishes 3-aryl-2-cyclohexenones in lower yield, but exceptional purity.
A Fe2(CO)9-mediated [5+1] cycloaddition of vinylcyclopropanes (VCPs) and CO to α, β-cyclohexenones has been developed. The reaction can tolerate aryl and aliphatic groups at the α-position of VCPs, while VCP substrates with vinyl or alkynyl substitutions are not suitable ones. In addition, this reaction can also be used to synthesize bicyclic rings if an aryl group is attached to the vinyl moiety of