Structural characterization of an enantiomerically pure amino acid imidazolide and direct formation of the beta-lactam nucleus from an alpha-amino acid.
Decomposition of a diazo beta-ketoamide derived from N-trityl serine imidazolide and N-protected acetanilides provides, instead of the expected 3-acyloxindole product, an enantiomerically pure (EP) beta-lactam. The amino acid stereocenter is incorporated, the second chiral center is induced, and trityl protection of the beta-lactam ring is realized for the first time. The desired 3-acyloxindole is obtained from oxindole and Tr-Ser(OBn)-imidazole, the X-ray of which provides the first structural determination of an EP amino acid imidazolide.
Gerstenberger
Brian S
BS
Department of Chemistry and Biochemistry, University of California, Santa Cruz, California 95064, USA.
Lin
Jinzhen
J
Mimieux
Yvette S
YS
Brown
Lauren E
LE
Oliver
Allen G
AG
Konopelski
Joseph P
JP
D000083:Acetanilides / Q000737:chemistry; D000596:Amino Acids / Q000737:chemistry; D007093:Imidazoles / Q000737:chemistry*; D007211:Indoles / Q000138:chemical synthesis / Q000737:chemistry; D015394:Molecular Structure; D012694:Serine / Q000737:chemistry; D013237:Stereoisomerism; D047090:beta-Lactams / Q000138:chemical synthesis*
D000083:Acetanilides; D000596:Amino Acids; D007093:Imidazoles; D007211:Indoles; D047090:beta-Lactams; D012694:Serine