Levoglucosenone-derived precursors for the stereoselective synthesis of methylene-expanded analogues of C-nucleosides

Levoglucosenone as a starting material for cascade continuous-flow synthesis of (R)-γ-carboxy-γ-butyrolactone

The global imperative to shift towards renewable and sustainable resources has spurred significant interest in exploring and utilizing platform chemicals derived from renewable feedstocks. Among these, levoglucosenone (LGO) and Cyrene™ have emerged as promising candidates. LGO, derived from the pyrolysis of cellulose and hemicellulose, exhibits structural versatility, making it an attractive starting material for various valuable products. Its chemical transformations can yield a diverse array of derivatives, including levulinic acid, furan derivatives, and intermediates for pharmaceutical and agrochemical synthesis, as well as bio-based materials such as bioplastics and resins. Cyrene™, produced through the hydrogenation of LGO, serves as a renewable, biodegradable, and non-toxic dipolar aprotic solvent, offering sustainability advantages for green chemistry applications. Herein we report our results on the continuous-flow cascade transformation of LGO into Cyrene™ and then (R)-γ-carboxy-γ-butyrolactone in good yields with an additional mechanistic investigation for the Baeyer-Villiger oxidation of Cyrene™.

Bio-available Solvent Cyrene: Synthesis, Derivatization, and Applications

The development of green solvents is one of the key tenets of Green Chemistry as solvents account for the majority of waste stemming from the production of the chemicals on which we have all come to rely. An important class of solvents is the dipolar aprotics, which include N,N-dimethylformamide (DMF) and N-methyl-2-pyrrolidone (NMP). In addition to being derived from non-renewable resources, these solvents are also under increased regulatory pressures that will limit their industrial applications. This Concept concerns the bio-available solvent Cyrene (dihydrolevoglucosenone) as a potential replacement for toxic dipolar aprotic solvents. An emphasis is placed on examining the strengths and weaknesses of Cyrene as a solvent and is accomplished by looking at the synthesis, derivatization, and application in synthetic protocols of Cyrene. With respect to the Twelve Principles of Green Chemistry, this Concept describes a bio-available solvent that should have a disruptive effect on the use of traditional industrial dipolar aprotic solvents.