beta-lactams as versatile intermediates in alpha- and beta-amino acid synthesis

The use of beta -lactams as synthetic intermediates has recently found cons iderable interest, driven by the accessibility of enantiomerically pure bet a -lactam building-blocks and by the discovery of selective methods for the beta -lactam ring opening. N-1-C-2 and C-2-C-3 bond cleavage of beta -lact ams can now be effected cleanly by different nucleophiles, in an intra- or intermolecular fashion, under isomerization-free conditions. By this way, a n array of diverse, densely functionalized, cyclic as well as open chain, a lpha- and beta -amino acid derivatives, including peptides. have been synth esized. Examples from our laboratory and from others are provided. 1 Introduction 2 Ring Opening at N-1-C-2 Bond of beta -Lactams 2.1 Ring Opening by Oxygen Nucleophiles. beta -Amino Esters and Related Pro ducts 2.2 Ring Opening by Nitrogen Nucleophiles. beta -Amino Amides and beta -Ami no Acid-Derived Peptides 2.3 Ring Opening by Carbon Nucleophiles. beta -Amino Ketones and Related Pr oducts 3 Ring Opening at C-2-C-3 Bond of beta -Lactams 3.1 NCAs Bearing Side Chains from Non-Proteinogenic alpha -Amino Acids 3.2 NCAs of alpha,beta -Diamino Acids 3.3 NCAs of alpha -Branched mu -Amino Acids 4 Concluding Remarks and Prospects.