title: A preparation of N-Fmoc-N-methyl-alpha-amino acids and N-nosyl-N-methyl-alpha-amino acids.
abstract: A convenient route for the synthesis of lipophilic N-Fmoc-N-methyl-alpha-amino acids and N-nosyl-N-methyl-alpha-amino acids, interesting building blocks to be used for the preparation of N-methylated peptides, is presented. Both nosyl- and Fmoc-protected monomers are accessible, so these compounds can be used in solution as well as in solid phase peptide synthesis. The methodology is based on the use of benzhydryl group to protect temporarily the carboxyl function of N-nosyl-alpha-amino acids and on the subsequent methylation of the N-nosyl-alpha-amino acid benzhydryl esters with diazomethane. The benzhydryl esters offer several beneficial features such as simple preparation, stability to methylation and selective deprotection under mild conditions. The overall procedure is highly efficient in that the adopted conditions keep the chiral integrity of amino acid precursors and the process does not require chromatographic purification of the methylated products.
authors.affiliation: Dipartimento di Scienze Farmaceutiche, Università della Calabria, Via P.Bucci, Cubo 15/C, 87036, Arcavacata di Rende (CS), Italy.
authors.forename: Maria Luisa
authors.initials: ML
authors.lastname: Di Gioia
authors.forename: Antonella
authors.initials: A
authors.lastname: Leggio
authors.forename: Angelo
authors.initials: A
authors.lastname: Liguori
authors.forename: Francesca
authors.initials: F
authors.lastname: Perri
authors.forename: Carlo
authors.initials: C
authors.lastname: Siciliano
authors.forename: Maria Caterina
authors.initials: MC
authors.lastname: Viscomi
mesh_terms: D015394:Molecular Structure; D010455:Peptides / Q000138:chemical synthesis* / Q000737:chemistry
chemical_list: D010455:Peptides