SYNTHESIS AND STEREOCHEMISTRY OF OPTICALLY-ACTIVE SELENONIUM IMIDES

Diastereoisomeric mixtures of oxycarbonyl]phenyl(methyl)selenonium-N-t oluene-4'- sulfonimides (dia.-1) and hyloxycarbonyl]phenyl(2',4',6'-tr iisopropylphenyl) selenonium-N-toluene-4''-sulfonimides (dia.-7) were synthesized. Optical resolution by the fractional recrystallization of dia.-7 from methanol gave the optically pure (-)-selenonium imide as stable crystals. The absolute configuration around the selenium atom w as determined to be S based on the CD spectra. The kinetics for the ep imerization by pyramidal inversion of the optically active selenonium imide were studied.