Publisher Summary The derivatives of tetramic acid are found in a number of natural substances. One example is tenuazonic acid 3 that was isolated from a culture filtrate of Alternaria tenius . Much work on the isolation of tenauzonic acid from plant is now being reported, owing to its interesting pharmaceutical properties. For this reason, numerous partial and total syntheses are described for tenuazonic acid in this chapter, as well as for the more complex tetramic acid derivatives tirandamycin 4 and streptolydigin 5. Much synthetic work to be reported in the chapter is approached with the goal of providing new biologically effective compounds. The majority of syntheses for tetramic acids described in the literature follows a strategy that is derived from the retrosynthetic analysis of tetramic acid derivatives. The chapter provides an overview of the chemistry of the 3-acyl-4-amino-1,5-dihydro-2-pyrrolones. The C-5 carbon atom of the pyrrolone ring is a stereo center that can be provided by natural derivatives of amino acids.

Advances in Tetramic Acid Chemistry

Pyrrolidine-2,4-diones, prepared from the corresponding α-amino acid esters by condensation with ethoxycarbonylacetic acid, Dieckmann cyclisation, and hydrolysis–decarboxylation, are acylated at C-3 by the acid chlorides of saturated, unsaturated, and arenecarboxylic acids in the presence of Lewis acids. The most efficient protocol involves boron trifluoride–diethyl ether as Lewis acid, isolation of the neutral boron difluoride complexes of the 3-acyltetramic acids, and their subsequent methanolysis. The quaternary ammonium enolates of 5-substituted pyrrolidine-2,4-diones undergo isomerisation to the exocyclic Δ5,6-isomers during O-acylation with acid chlorides.

Acylation of pyrrolidine-2,4-diones: a synthesis of 3-acyltetramic acids. X-Ray molecular structure of 3-[1-(difluoroboryloxy)ethylidene]-5-isopropyl-1-methyl-pyrrolidine-2,4-dione

A concise route to a key intermediate in the total syntheses of (+)-tirandamycic acid and (-)-tirandamycin a †

Synthesis and evaluation of a putative acyl tetramic acid intermediate in tenellin biosynthesis in Beauveria bassiana. A new role for tyrosine

A new pyrone strategy for the synthesis of 3-acyltetramic acids

Synthese du reactif d'Emmons diethoxyphosphoryl-3' acetonyl-3 hydroxy-4 R-1 pyrroline-3one-2 (R=dimethoxy-2,4 benzyl) a partir de N-R glycinate d'ethyle, de bromure de bromo-4 acetoacetyl et de diethylphosphite de potassium Reactions d'aldehydes avec ce reactif

R. H. Schlessinger

Papers

A versatile 3-acyltetramic acid reagent