Anionic Polymerization of O‑Benzyl and O-tert-Butyldimethylsilyl Dienes Derived from Myrcene to Yield Functional...

We report a concise route to two functionalized myrcene-based monomers via ozonolysis of myrcene, followed by the addition of benzyl or tert-butyldimethylsilyl groups to protect the alcohol functionality, allowing these monomers to be polymerized by anionic polymerization (AP). Both protected monomers undergo controlled homopolymerization and copolymerization with isoprene in THF solution to form polymers containing varying levels of functional group incorporation. DOSY NMR was used to monitor chain propagation kinetics in cyclohexane solution, revealing that the addition of ca. 7 mol % of functionalized OBn diene into a copolymerization with isoprene was sufficient to change the microstructure of the resulting polymer from ca. 6.5% 3,4-polymer to ca. 30% 3,4- (the remainder being 1,4-polymer). Removal of the TBS group using TBAF, or palladium-catalyzed hydrogenation of the Bn group with concomitant reduction of the alkenes, provides access to unsaturated or saturated hydroxyl-functional polymers, respectively. This work establishes a convenient method to produce ether-containing monomers from myrcene and their use in AP.