The Preparation of New C(α)-Dianions

Abstract For more than a decade, Hauser et. al. carried out rather extensive investigations on the preparation and reactions of the multiple anions of β -diketones and related materials. Once the conditions for the preparation of a particular multiple anion seemed established, three reactions were usually attempted with the new multiple anion: alkylations with reagents such as benzyl chloride2, Aldol-type condensations with aldehydes or ketones3 such as benzaldehyde and benzophenone, and Claisen-type condensations with esters such as methyl benzoate4. Other electrophilic reagents, such as nitriles5 and isocyanates6, were also condensed with certain of these multiple anions in selective situations; however, the alkylations, acylations, and carbonyl additions received the greatest amount of attention7. In some cases only one of the three types of reactions (Aldol) worked well8; however this did not mean that conditions could not be found for the other two reaction types. In addition, the synthetic potential...