2002 amino acids, peptides

amino acids, peptidesU 0400

19 - 187Reversible Diastereoselective Photocyclization of Phenylglyoxy-lamides of α-Amino Acid Methyl Esters to 3-Hydroxy β-Lactams.— Phenylglyoxylamides (III) are easily available by condensation of aminoesters (I) with phenylglyoxylic acid. Their irradiation at λ = 300 nm resultsin cyclization to β-lactams in high yields. The cyclization is completelyreversible in the absence of trace amounts of acid. — (GRIESBECK, AXELG.; HECKROTH, HEIKE; Synlett (2002) 1, 131-133; Inst. Org. Chem., Univ.Koeln, D-50939 Koeln, Germany; EN)

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