Biocatalytic synthesis of the Green Note -2-hexenal in a continuous-flow microreactor.

The biocatalytic preparation of -hex-2-enal from -hex-2-enol using a novel aryl alcohol oxidase from (AAOx) is reported. As O-dependent enzyme AAOx-dependent reactions are generally plagued by the poor solubility of O in aqueous media and mass transfer limitations resulting in poor reaction rates. These limitations were efficiently overcome by conducting the reaction in a flow-reactor setup reaching unpreceded catalytic activities for the enzyme in terms of turnover frequency (up to 38 s) and turnover numbers (more than 300000) pointing towards preparative usefulness of the proposed reaction scheme.