Single-handed helical polyethers synthesized via anionic polymerization of optically active 3-(9-alkylfluoren-9-yl)propene oxides

A series of optically active 3-(9-alkylfluoren-9-yl)propene oxides were synthesized by the reaction of 9-alkylfluoren-9-yllithium with the optically active epichlorohydrin at −70 °C and polymerized using KOH as an initiator. The molecular weight of the poly(3-(9-alkylfluoren-9-yl)propene oxide)s is larger than that of poly(4,4,4-triphenyl-1-butene oxide), which had been proved to take stable helical conformation in solution, and their molecular weight distributions were narrower (Mw/Mn = 1.02 to 1.09) than poly(4,4,4-triphenyl-1-butene oxide). By investigating of chiroptical properties of a series of polymers derived from optically active epoxide, it is suggested that the poly(3-(9-alkylfluoren-9-yl)propene oxide)s keep one-handed helical conformation in solution.