Copoly-β-amides

This thesis is concerned with the synthesis of β -amino and W-amino acid peptide derivatives which may be suitable monomers for polycondensation reactions.
Two main investigations have been undertaken; the oxazinone route was found to be unfavourable due to difficulty in purification and isolation of the monomers. The alternative active ester route met with success and a detailed study of the polymerisation of f -alanine trichlorophenyl esters is discussed. Other classes of more nucleophilic active esters were found to be unstable but could be coupled with a sterically hindered amino acid residue to afford dipeptides in good yield.
Methods of coupling for the preparation of Y-aminobutyric and ἐ -aminohexanoic acid derivatives were investigated. Under standard coupling conditions β-aminopivalic acid did not form active esters, probably due to steric hindrance at the carboxyl terminus. Finally the synthesis of N-protected peptides via salt formation was found to be applicable to both β and ὠ-amino acid peptides.