Allysine peptides and derivatives

Allysine, which is synthesized enzymatically in vivo starting from lysine, is a very important crosslink precursor in proteins. We describe the chemical synthesis of allysine derivatives starting from 3,4‐dihydro‐2H‐pyran. Two independent synthetic routes to prepare allysine peptides and derivatives are presented. The synthesized compounds are characterized by spectroscopic methods including 13C‐n.m.r. The reactivity of the aldehyde function is shown to be extremely high. An unexpected nucleophilic attack of the allysine amide nitrogen upon the aldehyde group is described. This ring‐closure reaction is not expected to take place in native collagen; however, denatured peptides containing allysine may react similarly as the model peptides presented in this paper.