Japheth O. Ombito and Girija S. Singh* Pages 544 - 567 ( 24 )
The β-lactams constitute a well-known class of compounds having tremendous biological significance. Besides being a motif of biological interest, they serve as versatile synthons in organic chemistry. In fact, their easy accessibility in the laboratory by several methods combined with inherent reactivity of the β-lactam ring due to ring-strain places it among the most sought for substrate in the arsenal of synthetic organic chemists. Several chemical reagents, heat, and light promote its ring-opening, ring-expansions and rearrangement reactions yielding a wide variety of biologically relevant nitrogen-containing acyclic and heterocyclic compounds. In recent years, the reactivity of differently functionalized β-lactam rings towards diverse kinds of reagents has been investigated. These investigations exploit selective bond cleavage of the β-lactam nucleus via N1-C2, C3C4, C2-C3 or N1-C4 bond cleavage using simple reagents. The reduction of amide carbonyl group, thionation, and pyrolysis/photolysis have also been explored. These investigations have led to the discovery of many easy synthetic methods for biologically important classes of compounds such as β-amino acids, β-amino esters, amino sugars, amino alcohols, peptides, azetidines, and other heterocyclic compounds. This article discusses the advances made in the studies on the reactivity of βlactam ring during the last ten years.
Amide-reduction, amino acids, amino alcohols, aza-heterocycles, ring-opening, β-lactams. Amide-reduction, amino acids, amino alcohols, aza-heterocycles, ring-opening, β-lactams.
Chemistry Department, University of Botswana, P. Bag: 0022, Gaborone, Chemistry Department, University of Botswana, P. Bag: 0022, Gaborone