Task: Text Categorization
Input (English): One of these organic compounds is converted to an alkene by a diorganochromium compound in the Takai olefination. Compounds may be reduced to this functionality via the use of DIBAL-H (die-bahl aitch), and alkynes are formed by a reaction of these compounds with tetrabromomethane and triphenylphosphine named for Corey and Fuchs. When these organic compounds lack a hydrogen atom in the alpha position, their disproportionation can be induced by a base in the Cannizzaro reaction. These organic compounds are oxidized to carboxylic acids by a diamminesilver (I) complex, leading to the precipitation of metal onto the inside of the vessel, giving the positive "silver mirror" result of the Tollens test. For 10 points, name this special class of ketones with one R group being just hydrogen.
Output (English): Science