Base-Controlled Reactions through an Aldol Intermediate Formed between 2-Oxoaldehydes and Malonate Half Esters

A practical, atom-economical, base-directed, and highly efficient method for the generation of different selective products through a common aldol intermediate of 2-oxoaldehydes and malonate half esters is successfully developed. The addition of a strong basic environment (potassium tert-butwdde) catalyzed the synthesis of stable decarboxylative aldol products (a-hydroxy ketones), while the Doebner modification procedure resulted in decarboxylative elimination to (E)-alpha,beta-unsaturated esters in good yields. The application of this method in one pot and one pot/two steps with azoles helped to develop regioselective alpha- and beta-azolated products in appreciable yields.