Synthesis and absolute configuration of optically active selenoxides. X-Ray molecular structure of (–)se-4-menthyloxycarbonylphenyl 2,4,6-tri-isopropylphenyl selenoxide

Enantiomerically pure, stable 4-(methoxycarbonyl)phenyl 2,4,6-tri-isopropylphenyl selenoxide (–)-(3) was isolated by fractional recrystallization of diastereoisomeric 4-[(–)-menthyloxycarbonyl]phenyl 2,4,6-tri-isopropylphenyl selenoxide dia.-(1) followed by removal of the chiral source. The absolute configuration around the selenium atom was determined by X-ray crystallographic analysis of diastereomerically pure selenoxide (–)Se-(1).