1: (1R,4S)-methyl 4-(2,5-dimethyl-1H-pyrrol-1-yl)cyclopent-2-enecarboxylate With lithium hexamethyldisilazane in tetrahydrofuran T=-20°C; 1.16667 h; 2: 2-iodo-propane in tetrahydrofuran T=-20 - 20°C; 5 - 6 h;

1: (1R,4S)-methyl 4-(2,5-dimethyl-1H-pyrrol-1-yl)cyclopent-2-enecarboxylate With lithium hexamethyldisilazane in tetrahydrofuran T=-20°C; 0.5 h; 2: 2-iodo-propane in tetrahydrofuran T=-20 - 20°C; 4 - 5 h; 3: With water; ammonium chloride in tetrahydrofuran

Product distribution / selectivity;

1: With sodium hydroxide in methanol; water T=65°C; 16 h; 2: With hydrogenchloride in methanol; water T=10°C;