Fig. 2: Process routes for the production of 4,5-dimethyl-1,3-dioxolane.

Alternative process routes (R1 & R2) for the production of 4,5-dimethyl-1,3-dioxolane from glucose. Acetaldehyde is produced by microbes from glucose and separated consecutively. The obtained acetaldehyde is converted to acetoin in an enzymatic ligation step using an ThDP-dependent enzyme (formulated as whole lyophilized cell). In R1 acetoin is further converted to 2,3-butanediol (2,3-BDO) using an enzymatic reduction step using an alcohol dehydrogenase and separated from its reaction solvent. In R2 acetoin is separated from its reaction solvent and subsequently hydrogenated chemo-catalytically to 2,3-BDO by addition of H₂. In both process routes, the 2,3-BDO is inserted in ain add chemo-catalytic acetalization step under addition of CO₂ and H₂ to obtain 4,5-dimethyl-1,3-dioxolane. Finally, 4,5-dimethyl-1,3-dioxolane is purified.