Dimethylcarbonate-Assisted Ring-Opening of Biobased Valerolactones with Methanol

The methanolysis reaction of renewable γ-valerolactone and α-methyl-γ-valerolactone in the presence of dimethylcarbonate and under acid conditions can be tuned to yield selectively each of three acyclic biobased products: 4-hydroxy-methylpentanoate 1, 4-methoxy-methylpentanoate 2, and methyl-pent-3-enoate 3. The reaction was studied in batch and in continuous flow, and a reaction mechanism based on experimental and computational evidence was proposed. The protocol is based on a set of greener chemical technologies and was implemented in continuous flow.