1: (3S,5S)-3-isopropyl-5-((2S,4S)-4-isopropyl-5-oxo-tetrahydro-furan-2-yl)pyrrolidin-2-one With 4-(N,N-dimethlyamino)pyridine; triethylamine in isopropanol acetate T=40 - 45°C; 2: di-tert-butyl dicarbonate in isopropanol acetate T=40 - 45°C;

4-methylmorpholine N-oxide; tetrapropylammonium perruthennate in dichloromethane; acetonitrile T=20°C; Molecular sieveHeating / reflux; Product distribution / selectivity;

1: 4-bromo-1-methoxy-2-(3-methoxypropoxy)benzene With n-butyllithium in tetrahydrofuran; hexane T=-70°C; 2 h; 2: (3S,5S)-3-isopropyl-5-((2S,4S)-4-isopropyl-5-oxotetrahydro-furan-2-yl)-2-oxopyrrolidine-1-carboxylic acid tert-butyl ester in tetrahydrofuran; hexane T=-70 - -50°C; 3: With water; citric acid in tetrahydrofuran; hexane T=0 - 5°C; 0.333333 h;

in tetrahydrofuran T=-70°C; 0.583333 h;

in tetrahydrofuran T=-10°C; 16 - 17 h;