Optically Pure Alkoxychlorosulfuranes. Synthesis and Transformation to Chiral Sulfoxides, N-p-Tosylsulfilimines, and Sulfonium Ylides

Optically pure alkoxychlorosulfuranes (1) have been prepared by using the 2-exo-hydroxy-10-bomyl group as a c h i tigand.The structure of 1 13 sulfurane (la) was confumed by H-nmr, C-nmr, and mass spectra Nucleophilic reaction of 1 with water and NaNHTs proceeded with retention of configuration to give optically pure sulfoxides (2) and N-p-tosylsulfiies (3).respectively.Sulfonium ylides (4) were obtained as mixtures of diastereomers by the reaction of 1 with NaCH(CQMe),.The absolute configuration of sulfilimime (3c) was determined by X-ray analysis.Hypervalent 10-S-4 organosulfur species (sulfuranes) are well-known as an intermediate in reactions of sulfoxides, s u l f i i i , sulfonium salt., and sulfides.'Some of them have been isolated by using the "Martin type" or oximate five-membered ring as a ligand.2Synthesis of optically active sulfuranes is interesting not only as a synthetic goal but also from the mechanistic point of view.Martin3ac and Kapovitssd have reported the synthesis of optically active sulfuranes.Hydrolysis of the sulfuranes proceeds with retention of configuration to give optically active sulfoxides.Recently, we have succeeded in the synthesis of optically pure selenuranes by using the 2-exo-hydroxy-10-bomyl group as a c h i d 199