A Convenient On-Site Oxidation Strategy for the N-hydroxylation of Melanostatin Neuropeptide using Cope Elimination

In this work, a convenient synthetic protocol for the unprecedented N-hydroxylation of proline residue in Melanostatin (MIF-1) neuropeptide is reported. This methodology is grounded on the incorporation of N-(cyanoethyl)prolyl residue followed by on-site oxidation by Cope elimination with m-chloroperbenzoic acid, exploring the unrecognized dual role of the cyanoethyl group as an effective N-protecting group under peptide synthesis conditions and as a suitable leaving group during the chemoselective on-site N-oxidation. Following this protocol N-hydroxy-MIF-1 is obtained with 78% global yield from N-(cyanoethyl)-L-proline. This synthetic approach opens a new avenue for access to N-hydroxylated Melanostatin analogs with direct application in neurochemistry and Parkinson’s research.