Ring-Closure Reactions through Intramolecular Displacement of the Phenylselenonyl Group by Nitrogen Nucleophiles: A New Stereospecific Synthesis ofN-Tosyl andN-Benzoyl-1,3-oxazolidin-2-ones fromβ-Hydroxyalkyl Phenyl Selenides
3-oxazolidin-2-ones from the easily available beta-hydroxyalkyl phenyl selenides is presented. After transformation into the N-tosyl or N-benzoyl carbamates, the selenides were oxidized to the corresponding selenones. The key step of the process is the ring-closure reaction, which occurs by stereospecific intramolecular nucleophilic substitution of the selenonegroup by the nitrogen atom of the carbamate. Enantiomerically