Acyl migration, novel intramolecular

Y Sohma, M Sasaki, Y Hayashi, T Kimura, Y Kiso. Novel and efficient synthesis of difficult sequence-containing peptides through O-N intramolecular acyl migration reaction of O-acyl isopeptides. Chem Commun 124, 2004. 

Crossover experiments have been used to establish that the novel N to C acyl migration reaction of acyclic imides (69), to give o -amino ketones (70), proceeds by intramolecular reaction of the base-generated carbanion. ... 

The formation of tluorinated Q -hydroxy-jS-imino esters (180) by treatment of fluorinated imino ethers (179) with lithium 2,2,6,6-tetramethylpiperidide has been reported. A possible explanation for this interesting intramolecular rearrangement is proposed in Scheme 64. Acyclic imides derived from primary benzylic amines and amino acid esters have been found to undergo a novel nitrogen to carbon acyl migration via a base-generated carbanion to yield the corresponding a-amino... 

Sohma Y, Sasaki M, Hayashi Y, Kimura T, Kiso Y. Design and synthesis of a novel water-soluble A(il-42 isopeptide an efficient strategy for the preparation of Alzheimer s disease-related peptide, Api-42, via O-N intramolecular acyl migration reaction. Tetrahedron Lett. 2004 45 5965-5968. 

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