Synthesis and optical studies of L‐methionine oligopeptides in solution

A series of L ‐methionine oligomers [BOC‐(Met) n ‐OMe] ( n = 2–7) and the corresponding diastereomeric di‐ and tripeptides were synthesized using the mixed anhydride method. Oligomers prepared in this manner were optically pure and were obtained in reasonable yield. Preliminary optical examination of the peptides suggests that secondary structures may begin forming in the pentamer or hexamer in trifluoroethanol. BOC‐(Met) 4 ‐OMe and BOC‐(Met) 5 ‐OMe were also synthesized using an insoluble resin containing BOC‐ L ‐methionine as the nitrophenol active ester.