Synthetic studies on threonines. The preparation of protected derivatives of D-allo-and L-allo-threonine for peptide synthesis

P Lloyd-Williams, A Sánchez, N Carulla, T Ochoa…

Index: Lloyd-Williams, Paul; Sanchez, Agusti; Carulla, Natalia; Ochoa, Teresa; Giralt, Ernest Tetrahedron, 1997 , vol. 53, # 9 p. 3369 - 3382

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Citation Number: 11

Abstract

N-Acetylated threonine derivatives, having tert-butyl or benzyl-based side-chain protection, form isolable 5 (4H)-oxazolones on treatment with N-ethyl-N′-3-dimethylaminopropyl carbodiimide. N-chloroacetylated threonine derivatives, on the other hand, do not form oxazolones so readily. The N-acetylated oxazolones are easily epimerized and lead to diastereoisomeric mixtures of threonine derivatives on hydrolysis with dilute aqueous acid ...