A practical and environmentally friendly protocol for synthesis of α‐deuterated carboxylic acids

α‐deuterated carboxylic acids have been synthesized from the corresponding malonic acids via hydrogen/deuterium exchange and decarboxylation in presence of D2O. The method is general, mild and efficient and does not require organic solvents or other additives. Yields range between 83% and 94% and purification was not necessary. Starting materials were easy accessible and the α‐deuterated carboxylic acids may easily be transformed to other labeled compounds such as alcohols, aldehydes, esters, and amides. Characterization with NMR confirmed purity and isotopic purity.