Preparation of 4-anilino-6-aryl-2H-pyran-2-ones from trilithiated acetoacetanilides and aromatic esters

Acetoacetanilide and 4′-chloroacetoacetanilide were trilithiated with excess lithium diisopropylamide and condensed with several aromatic esters, followed by neutralization, separate acid cyclization, and rearrangements. After C-acylation of trilithiated acetoacetanilides and cyclization to 4H-pyran-4-ones, these compounds underwent multistep rearrangements to 4-anilino-6-aryl-2H-pyran-2-ones.Key words: pyranones, trianions, Claisen-type condensations, rearrangements.