The First Example of the 1-Chalcogene-Substituted Formylolefination of the Ketones and Aldehydes Using 1-Lithio-2-ethoxyvinyl Chalcogenides

Article abstract of DOI:10.1021/jo980487i

The α-chalcogene-substituted formylolefinations of ketones and aldehydes proceeded using 1-lithio-2-ethoxyvinyl chalcogenides/PPSE or TMSOTf to produce the α-chalcogenoformylolefinated products 4a-l in high yields. Tandem-formylolefmation provided the (2Z,4Z)-2,4-bis(chalcogeno)pent-2,4-dienals 5d,h,i and (2Z,4Z,6Z)-2,4,6-tris(phenylthio)hept-2,4,6-trienal derivatives 7d and 8d, respectively.