As the Achmatowicz pyranones can be directly synthesized from the lignocellulose-derived fivemembered furfuryl alcohols, it is easy to imagine a scenario where the six-membered Oheterocycles would only act as intermediate in a multi-catalytic cascade. The combination of a ringexpanding Achmatowicz oxidation with the herein presented ring-contracting borrowing hydrogen redox isomerization and a final enoate reduction would thus render an overall process in which the furan starting materials could be dearomatized in an enantioselective fashion through a transient pyranone. One of the major benefits of biocatalysis in general is the excellent mutual tolerance of different enzymes and the opportunity to merge multiple biocatalytic functions in a one-pot fashion, thereby eliminating isolation and purification steps that typically contribute to unnecessary product loss and overall poor sustainability factors. Thus, more step-economic and elegant catalytic cascades can be implemented (Scheme 5). Best results were obtained in a sequential biocatalysis setup where furfuryl alcohol 5a was first incubated with chloroperoxidase and glucose oxidase in order to furnish the pyranone intermediate. After adjustment of the pH of the buffer and addition of P2-G03 and evo030, clean formation of the dearomatized five-membered O-heterocycle was observed and 7a was generated in enantiopure form, whereupon addition of an enoate reductase (ERED207) and glucose dehydrogenase delivered the saturated g-lactone 14a in excellent optical purity. Here, an overall yield of 53% translates to an average yield per chemical step of 81%. The sequential three-step one-pot process involving six distinct enzyme catalysts thus enables a streamlined preparation of a saturated O-heterocyclic building block, found for example as core structure in the cavernosine terpene family, through a formal enantioselective water addition to the biorefinery waste furan, where the central borrowing hydrogen biocatalysis is complemented with both oxidative and reductive enzyme modules.