Macrocyclic peptides, 4. Preparations and enantioface‐differentiating abilities of 27‐ and 36‐membered ring peptides containing <i>N</i>,<i>N</i>′‐ethylene‐bridged dipeptides and glycine

Abstract

Abstract 27‐ and 36‐membered ring peptides were prepared using glycine, (2 S , 3′ S )‐4‐methyl‐2‐(2′‐oxo‐3′‐isobutyl‐1′‐piperazinyl) pentanoic acid ( 2 ) and (2 S ,3′ S )‐3‐phenyl‐2‐(2′‐oxo‐3′‐benzyl‐1′‐piperazinyl)propanoic acid as the units of peptides. The interactions of 1‐phenylethylammonium ( 1 ) and p ‐methoxy‐1‐phenylethylammonium bromides ( 11 ) with these cyclic peptides were studied by 1 H and 13 C NMR measurements in CDCl 3 . It was found from these results that the peptides distinguish the enantiomers ( R ‐ and S ‐isomers) of the substrates. Furthermore, it was shown that the enantioface‐differentiating abilities of 36‐membered ring peptides are superior to those of 27‐membered rings.