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Cyclol formation in peptide system tautomerism of N-(α-hydroxyacl)-amides

✍ Scribed by M.M. Shemyakin; V.K. Antonov; A.M. Shkrob; Yu.N. Sheinker; L.B. Senyavina

Publisher
Elsevier Science
Year
1962
Tongue
French
Weight
322 KB
Volume
3
Category
Article
ISSN
0040-4039

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✦ Synopsis

INTRAMOLECULAR interaction of amide groups with various functional groups (OH, SH, NH2) has been repeatedly advanced as the underlying cause for the specific properties of peptides or related compound such as ergot alkaloids, 1 the antibiotics bacitracin A2 and polymyxin M, 3 peptides containing cysteine, serine and threonine residues, 495 esterases 6 etc. In all cases the formation of unstable intermediates (cyclols) has been postulated. However, X = 0, S, NH this assumption had no experimental backing, being based only on indirect evidence; namely, enhanced reactivity of the amide group or formation of unexpected reaction products. Investigation of this problem on examples wherein the cyclols formed were more or less stable would therefore be of considerable theoretical interest. 1 A. Stall, Proar. Chem. Ora. Nat. Prod. 2, 114 (1952).

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