Synthesis of polymers bearing sulfoxide groups by oxidation of monothio-orthoesters and their rearrangement into carboxylic ester-containing monomers and polymers

Reaction of monomers, polymers and copolymers containing monothio-orthoester groups with meta-chloroperoxybenzoic acid in CH2Cl2 at 20°C affords the corresponding S-oxides. The chemoselective conversion of alkythio group into a sulfoxide moiety was achieved with monomers, polymers and copolymers bearing monothio-orthoester functionality to yield the first examples of sulfoxide monothio-orthoesters. These compounds are rather unstable and undergo a novel rearrangement to carboxylic esters and (co)polyesters at room temperature. The process is proposed as a convenient synthetic route for preparing (co)polymers bearing carboxylic ester functions in the side-chains.