TO 1-methyl-2-oxo-2-tetrahydro-1-H-1-pyrrolylethyl 2,6-dibromohexanoate (295 mg, 0.75 mmol), NaI (225 mg, 1.5 mmol), triethylamine (303 mg, 3.0 mmol) and tetrahydrofuran (4 mL) were added. Subsequently, allylamine hydrochloride (84.2 mg, 0.9 mmol) and tetrahydrofuran (4 mL) were added thereto. The mixture was stirred at 20° C. for 4 hours and then at 40° C. for 15 hours. It was confirmed with NMR analysis of the reaction solution that the conversion ratio was 100% and the diastereo ratio was 75:25.
