Absolute configuration of a diaryldiacyloxy spiroselenurane and resolutionof a carbon analog

The enantiomers of 3,3'-spirobi(3-selenaphthalide) (2) were obtained via di rect separation by liquid chromatography on a chiral stationary phase. Dete rmination of the absolute configuration was made by X-ray crystallography w ith the use of the anomalous dispersion technique. The first eluted (+)-for m (lambda = 302 and 365 nm) of 2 was found to have (S)-configuration. By a comparison of CD-spectra, the same (S)-configuration could be assigned to t he (+)-forms of the sulfur (1) and tellurium (7) analogs of 2. An asymmetri c dichloro-substituted spirobilactone (4) was also synthesized and separate d into its enantiomers. Relative configurations between 4 and its parent co mpound (3) were established from the corresponding chiroptical data obtaine d. Chirality 12: 71-75, 2000. (C) 2000 Wiley-Liss, Inc.