Acid catalysed methanolysis of 2,5-diazabicyclo[2.2.2]octane-3,6-diones: scope and limitations
摘要:
The selective methanolysis of 2,5-diazabicyclo[2.2.2]octane-3,6-dione systems is a key step in a synthetic procedure leading to 4-amino-6-oxo-2-piperidinecarboxylate systems. This reaction seems to be primarily governed by steric hindrance caused by the substituents at the 1 - and 4-bridgehead positions of the dione. In absence of bulky substituents the methanolysis is directed by the secondary or tertiary nature of the two lactam moieties. (C) 2004 Elsevier Ltd. All rights reserved.
Design and synthesis of novel type VI-like β-turn mimetics. Diversity at the i+1 and the i+2 position
摘要:
In this paper, a synthetic approach for functionalised 5-aminopiperidinone-2-carboxylate (APC) systems as non-pro cis-peptide bond containing external beta-turn mimics is presented. The scope and limitations of the synthetic method are discussed and the potential turn inducing properties of a model compound are evaluated by means of molecular modelling and NMR analysis. (C) 2004 Elsevier Ltd. All rights reserved.