| abstract |
The present invention refers to a new class of malonic acid derivatives of general formula In wherein R¹ and R², each independently, represent hydrogen or a carboxyl protecting group, and the residue R corresponds to the side-chain of the amino acids lysine, ornithine, tyrosine, cysteine, aspartic acid and glutamic acid wherein the additional functionalities are suitably protected. n The new compounds of the present invention are useful for preparing analogues of biologically active peptides wherein the direction of some amide bonds in which the amino acids lysine, ornithine, tyrosine, cysteine, aspartic acid or glutamic acid are involved, has been reversed. |