Selective continuous flow synthesis of hydroxy lactones from alkenoic acids

A novel approach to synthesize hydroxy lactones using flow chemistry is reported. The system could be applied to a variety of functionalized alkenoic acids allowing the simple and eco-friendly generation of lactonic products within one hour (50 min). The reaction was optimized in terms of efficiency, productivity, resources and eco-sustainability using an integrated flow process assisted by in-line work-up and purification. In one example, the method was scaled to deliver 22 mmol of the product.