It has been found that the optically active epoxide (R)-4,4,4-triphenyl-1-butene oxide [or its (S) isomer], which bears bulky pendant, can polymerize to form helical polyether. In our study, optically active epoxides and ring-sulfured compounds with fluorenyl substituent are necessary. Using fluorene and its derivatives to react with n-butyl lithium, the corresponding organic lithium salts can be given, and then, the optically active epichlorohydrin was added dropwise at －70 ℃, stirring to room temperature for several hours. According to regular treatment, the optically pure terminal epoxides with fluorenyl substituent were obtained. The ee values of epoxides are larger than 98%. To a solution of epoxy compounds in THF, was added NH₄SCN with stirring, and stirred for 24 h at room temperature. The solvent was evaporated in vacuo and the residue was separated by column chromatography. Optically pure ring-sulfured compounds were obtained and their ee values are greater than 97%. The products were analyzed by NMR, elemental analysis and polarimeter, and mechanism of the reaction was discussed.

Key words: epichlorohydrin, chirality, ring-sulfured compounds, asymmetric synthesis