Synthetic study on 2,2′-(1,4-phenylene)bis(3-alkyl-1H-inden-1-ones): The first application of a sodium enolate as a 'protecting group' in the Grignard reaction

Article abstract of DOI:10.1055/s-2008-1067043

A new series of 2,2'-(l,4-phenylene)bis(3-substituted-1H-inden-l-ones) were prepared and their structures were established by ¹H 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[lH-indene-l, 3(2H)-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.