1: 2-[(methoxymethylamino) carbonyl]-1-pyrrolidinecarboxylic acid, 1,1-dimethylethyl ester With diisobutylaluminium hydride in n-heptane; dichloromethane T=-78°C; 1.25 h; 2: With methanol in n-heptane; dichloromethane 3: (1-Diazo-2-oxo-propyl)-phosphonic acid dimethyl ester With water; potassium carbonate; Sodium potassium tartrate more than 3 stages;

potassium carbonate in methanol T=20°C; 15 h;