Upon treatment with DAST (diethylaminosulfur trifluoride) enantiopure 2-hydroxyalkylazetidines rearrange into 3-fluoropyrrolidines. The reaction is stereospecific and involves a bicyclic 1-azoniabicyclo[2.1.0]pentane intermediate which is regioselectively opened by a fluoride anion.
用
DAST(二乙
氨基三
氟化
硫)处理后,对映体纯的 2-羟基烷基氮杂
环丁烷重排为 3-
氟吡咯烷。该反应是立体有择的,涉及双环 1-azoniabicyclo[2.1.0]
戊烷中间体,该中间体被
氟阴离子区域选择性地打开。