Abstract: Pd(OAc)₂ (palladium acetate)/(S)-P-PHOS ((S)-2,2′,6,6′-tetramethoxy-4,4′-bis(diphenyl)phosphino)-3,3′-bipyridine) catalysis systems were applied to the alternating copolymerization of propene and CO in organic solvents to synthesize chiral polyketones. The diastereoselective reduction of a chiral polyketone using excess LiAlH₄ (lithium aluminum hydride) and NaBH₄ (sodium borohydride) as reducing agents gave a new class of optically active polyalcohol and the product yield was more than 90%. In the presence of various amounts of NaBH₄ (NaBH₄/carbonyl molar ratio of 0.5, 1, and 2), quantitative measurements of the intensity of the carbonyl absorbance at 200–400 nm in the UV (ultraviolet) spectrum showed a reduction of 29%, 71%, and 81%, respectively, for the carbonyl groups. The use of excess BH₃·THF (borane tetrahydrofuran complex) as a reducing agent resulted in a partial reduction of the carbonyl groups of the chiral polyketone. The molecular weight of the product was lower than that of the chiral polyketone and the molar optical rotations of the product varied with the reductive conditions.

Key words: palladium acetate, chiral diphosphous ligand, propene, carbon monoxide, chiral polyketone, reducing agent, chiral polyalcohol