The use of N-carbamoyliminium ion initiated reactions for the generation of spiroimidazolidin- 2-ones has been successfully exploited. Treatment of hydantoins with saturated alkyllithium and alkylmagnesium reagents gave the corresponding 4-hydroxyimidazolidin-2-one adducts. In the case of carbon-5 unsubstituted and carbon-5 monosubstituted hydantoins, dehydration of the intermediate 4-hydroxy derivatives occurred during workup to yield ...
![5-methyl-3-[2-(2-methylphenyl)ethyl]imidazolidine-2,4-dione Structure](https://image.chemsrc.com/caspic/348/96040-47-0.png)