The synthesis of optically active P-heterocycles

Article abstract of DOI:10.1002/hc.20599

Optically active 1-alkoxy- and 1-amino- 3-phospholene oxides were synthesized by the reaction of the corresponding 1-chloro-3-phospholene oxides with (1 R,2S,5R)-(-)menthol and (S)-(-)-α- phenylethylamine. The 3-methyl-3-phospholene oxides were subjected to dichlorocyclopropanation under liquid-liquid phase transfer catalytic conditions to afford the 3-phosphabicyclo[3.1.0]hexane 3-oxides as a mixture of four diastereomers. Thermolysis of the menthyl-phosphabicyclohexane oxides led to the corresponding 1 2-dihydrophosphinine oxide as a diastereomeric mixture of two double-bond isomers. As a result of additional steps, the dichlorocarbene addition reaction of the 1-menthyl- 3,4-dimethyl-3-phospholene oxide resulted in eventually, the formation of a 4-dichloromethylene-1,4-dihydrophosphinine oxide.