One drawback to this CrO3 oxidation is that it takes place under acidic conditions, and sensitive molecules sometime undergo side reaction. In such cases, the laboratory oxidation of an aldehyde can be carried out using a solution of silver oxide, Ag2O, in aqueous ammonia, the so-called Tollens reagent. Aldeehydes are oxidized by the Tollens reagent in high yield without harming carbon-carbon double bonds or other functional groups in the molecule.