Synthesis and Postpolymerization Modification of One-Pot ω-Pentadecalactone Block-like Copolymers

We report the one-pot copolymerization of omega-pentadecalactone (PDL) to produce tri- and diblock-like copolymers with the ability to undergo postpolymerization modification. The epsilon-substituted epsilon-lactone (epsilon SL), menthide (MI), was copolymerized with PDL to introduce side chain functionality into poly(omega-pentadecalactone) (PPDL) copolymers. The copolymerization was followed by quantitative C-13 NMR spectroscopy, which revealed that the polymerization of MI occurred before the incorporation of PDL into the polymer chain to form a block-like copolymer. Transesterification side reactions were not found to occur interblock, although intrablock transesterification side reactions occurred only within the PPDL section. The same effect was demonstrated across a range of relative molar equivalents of monomers, and the generality of the approach was further demonstrated with the copolymerization of PDL with other epsilon SL monomers. Finally, the copolymerization of PDL with an alkene-functionalized epsilon SL was shown to produce one-pot PDL block-like copolymers that could undergo postpolymerization modification by thiol-ene addition to produce block copolymers with a range of characteristics in a simple procedure.