The present invention provides a process comprising substitution of an acceptor molecule comprising a group -XC(O)- wherein X is O, S or NR8, where R8 is C1-6 alkyl, C6-12 aryl or hydrogen, with a nucleophile, wherein the acceptor molecule is cyclised such that the said nucleophilic substitution at -XC(O)- occurs without racemisation. This process has particular application for the production of a peptide by extension from the activated carboxy-terminus of an acyl amino acid residue without epimerisation.
本发明提供了一种工艺,包括用亲核物取代由基团-XC(O)-组成的受体分子,其中 X 是 O、S 或 NR8,其中 R8 是 C1-6 烷基、C6-12 芳基或氢,受体分子被环化,使所述亲核取代在-XC(O)-处发生而不发生外消旋化。这种工艺特别适用于通过从酰基
氨基酸残基的活化羧基末端延伸生产肽,而不会发生外延。