Enantioselective alternating copolymerization of carbon monoxide with 1-heptene was carried out using palladium catalyst modified hy 1

4-3

6-dianhydro-2

5一dideoxy-2

5-bis(diphenylphosphino)-L-iditol (DDPPI)．The chiral diphosphine was proved to be effective at enantioselective copolymerization．The pure poly(1

4-ketone) was obtained by dissolving the copolymer containing spiroketal and 1

4-ketone units in 1

1

1

3

3

3-hexafluoro-2-propanol and reprecipitating with methanol．Optical rotation

elemental analysis

spectra of 1H-NMR

13C-NMR and IR showed that our copolymer was optically active

isotatic

alternating poly(1

4-ketone) structure．The copolymerization was carried out at 45℃ for 48 h．Molecular weight：Mn=4.02×103

Mw／Mn=1.55 (GPC measurements with polystyrene standards)．Optical rotation：[α]20589=+63。 (CH2Cl2

5.0 mg／mL)．Tm=194℃

Tg=11℃．