Synthetic Study on 2,2-(l,4-Phenylene)bis(3-alkyl-l/T-inden-l-ones): The First Application of a Sodium Enolate as a 'Protecting Group' in the Grignard Reaction

摘要

A new series of 2,2'-(l,4-phenylene)bis(3-substituted-l//-inden-l-ones) were prepared and their structures were established by 'H and 13C NMR, IR, and HRMS spectroscopy. One molecular structure was further confirmed by single crystal X-ray crystallography. The synthetic mechanism was studied in detail. The key step involves the reaction of the Grignard reagent with the sodium enolate of 2,2'-(l,4-phenylene)bis[l//-indene-l,3(2//)-di-one]. This is the first example of a sodium enolate being employed as the protecting reagent for a carbonyl group in the Grignard reaction.