“…10 In particular, the drop-in synthesis of bio-based products in the short to mid-term can have a much larger impact at the industrial level than the synthesis of completely new biomolecules or biopolymers (i.e., PHA), by-passing some of the critical barriers to commercial development, such as the market acceptance, the rate at which new bio-products may be introduced into the market, the process scalability, and the possibility to use the existing assets and plants for the production. 11 On the other hand, the main requirements that drop-in products should have for entering the market are a competitive price, comparable technical performances and a better environmental prole (i.e., lower environmental footprint) than the fossil-based alternatives. 12 Here, our interest is oriented to crotonic acid (CA), a drop-in compound that can be obtained both from a fossil-based production route and from the depolymerization of PHA.…”