Ring Closure Reactions by Intramolecular Displacement of the Phenylselenonyl Group by Nitrogen Nucleophiles. A New Stereospecific Synthesis of N-Tosyl and N-Benzoyl-1,3-Oxazolidin-2-ones from beta-Hydroxyalkyl Phenyl Selenides.

A new and convenient method for the stereospecific synthesis of variously substituted 1,3-oxazolidin-2-ones from the easily available b-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 selenone group by the nitrogen atom of the carbamate. Enantiomerically pure 1,3-oxazolidin-2-one derivatives can be easily prepared by using enantiomerically pure b-hydroxyalkyl phenyl selenides as starting materials