Optically active cyclic poly(ether sulfone)s based on chiral 1,1 '-bi-2-naphthol

Optically active cyclic poly(ether sulfone)s are prepared from 4-fluorophen yl sulfone and (R)- or (S)-1,1'-bi-2-naphthol. The measurement of MALDI-TOF MS shows that the product is composed of a series of cyclic and linear oli gomers where the repeating unit number (n) is from 2 to 12, from which the cyclic dimers (n=2), and cyclic trimer (n=3) have been separated from their homologous compounds by TLC successfully. Specific optical rotation [alpha ](D)(25) is -583.0 for (R)-cyclic dimer, +588.0 for (S)-cyclic dimer, +22.7 for (R)-cyclic trimer, and -20.3 for (S)-cyclic trimer. Their properties a re also determined by other methods, such as H-1 NMR and CD etc. (C) 1998 E lsevier Science Ltd. All rights reserved.