Sustainable Synthesis and Polycondensation of Levoglucosenone-Cyrene-Based Bicyclic Diol Monomer: Access to Renewable Polyesters.

The already-reported, low-yielding, and non-sustainable Et3 N-mediated homocoupling of levoglucosenone (LGO) into the corresponding LGO-CyreneTM diketone has been revisited and greened-up. The use of methanol as both a renewable solvent and catalyst and K2 CO3 as a safe inorganic base improved the reaction significantly with regards to yield, purification, and green aspects. LGO-CyreneTM was then subjected to a one-pot, H2 O2 -mediated Baeyer-Villiger oxidation/rearrangement followed by an acidic hydrolysis to produce a new sterically hindered bicyclic monomer, 2H-HBO-HBO. This diol was further polymerized in bulk with diacyl chlorides to access new promising renewable polyesters that exhibit glass transition temperatures (Tg ) from -1 to 81 °C and a good thermostability with a temperature at which 50 % of the mass is lost (Td50 % ) of 349-406 °C.