A novel synthetic method for crown ethers by a redox reaction utilizing the intermediate from diphenyldiazomethane and 2,3-dichloro-5,6-dicyanobenzoquinone
A novel synthetic method for crown ethers by a redox reaction utilizing the intermediate from diphenyldiazomethane and 2,3-dichloro-5,6-dicyanobenzoquinone
been developed where salicylic acid ketals react with alkynes to afford substituted chromones. A mechanistic rationale is proposed, implying beta-elimination of ketone from ring strained seven-membered nickelacycle to generate a five-membered oxa-nickelacycle intermediate.