Biosynthesis of agglomerin A: stereospecific incorporation of pro-R- and pro-S-hydrogens at sn-C-3 of glycerol into the branched C3 moiety

Tetramic and tetronic acids: an update on new derivatives and biological aspects

Significant developments in the isolation of tetramic acids and tetronic acids, in the elucidation of their biosyntheses and their biological activities and in laboratory syntheses are reviewed with a focus on those derivatives with medicinal and pharmacological relevance. Important new members of the title compound families isolated since the year 2000 are covered as well as new biological aspects of some earlier congeners.

Mechanisms for incorporation of glycerol-derived precursors into polyketide metabolites

Several polyketide secondary metabolites are shown by feeding experiments to incorporate glycerol-derived 3-carbon starter units, 2-carbon extender units, or 3-carbon branches into their hydrocarbon chains. In recent years, genetic studies have begun to elucidate the mechanisms by which this occurs. In this article we review the incorporation of glycerol-derived precursors into polyketides and propose new mechanisms for the incorporation processes.

Solution-phase and solid-phase syntheses of enzyme inhibitor RK-682 and antibiotic agglomerins

The enzyme inhibitor RK-682 (5R)-(+)-1 was prepared in solution and on a solid support from (2R)-glycerates in five steps and ca. 40% overall yield. Key steps were a ring-closing tandem addition-Wittig alkenation reaction of the respective protected or immobilized glycerates with the ylide Ph(3)PCCO and the 3-acylation of the tetronic acids thus obtained with palmitic acid. A similar route extended by a mesylation-elimination sequence led to antibiotic agglomerins A-C 2 featuring 3-acyl-5-methylidenetetronic acid structures.