Asymmetric oxidation of poly(vinyl sulfides) with percamphoric acid, aspergillus niger, and penicillium notatum

The asymmetric oxidation of poly(phenylvinyl sulfide) (poly‐Ph VS) and poly(t‐butylvinyl sulfide) (poly‐t‐BuVS) was carried out with optically active percamphoric acid, and the optically active polysulfoxides were obtained. The values of the specific rotation for the oxidation products of poly‐PhVS and poly‐t‐BuVS were + 1.0 (having 56% of sulfoxide unit contents) and +9.1 (49%), respectively. The specific rotation of the product increased with increasing the contents of sulfoxide units. The optical rotatory dispersion curves of the oxidation products of poly‐PhVS and poly‐t‐BuVS were positive curves and were found to fit the simple Drude equation. The λc values of the oxidation products (poly‐PhVS, 271 mμ; poly‐t‐BuVS, 212 mμ) suggested that the chromophore which caused optically activity was the sulfoxide group. Similarly, the asymmetric oxidation of t‐BuVS–MMA copolymer, t‐BuVS–styrene copolymer, and PhVS–MMA copolymer was carried out, and the optically active copolysulfoxides were obtained. Furthermore, the biosynthetic oxidation of poly‐PhVS and PhVS–maleic anhydride copolymer treated with aqueous KOH was carried out using Aspergillus niger or Penicillium notatum in Czapeck solution, and the optically active polymers were obtained.