The oxidation of E-methylene unit in lysine derivatives is well-known.'-'We employed the method of oxidation with permanganate in aqueous solution elaborated by Kasprzykowska and Liberek5 to accomplish the first step of the synthesis. Since the N-acylamide group present in the oxidation product is susceptible to both basic and acidic hydrolysis leading to dicarboxy amino acid and benzyl carbamate, 8 the introduction of Fmoc was carried out ...