copper(l) iodide; caesium carbonate; (2S,4R)-2-carboxy-4-hydroxypyrrolidine in N,N-dimethyl-formamide T=80°C; 24 h; Inert atmosphere;

1: With sulfur; [2,2']bipyridinyl; copper(l) iodide; potassium carbonate in 1-methyl-pyrrolidin-2-one T=110°C; 24 h; Inert atmosphere; 2: With pyridine; N-methoxyamine hydrochloride in 1-methyl-pyrrolidin-2-one T=110°C; 3 h; Inert atmosphere;