Pyrimidine-substituted examples of this functional group are autocatalytically alkylated in the Soai reaction. This functional group is condensed with ammonia and hydrogen cyanide in the first step of the Strecker (10[1])synthesis. (10[1]-5[1])Applying (-5[1])DIBAL-H (-5[2])(DIE-bow H), followed by aqueous workup, reduces nitriles to this functional group. (10[3]-5[1])Treating a primary alcohol with pyridinium (10[1])chlorochromate (-5[1])[emphasize] (10[3])mildly (10[1])oxidizes it to (-5[1])this (10[1])functional (10[2]-5[2])group, rather than a carboxylic (10[7])acid. A (-5[1])“silver (10[1])mirror” (10[2])forms (10[1])when this (10[3])functional (-5[1])group produces a (10[1])positive (10[1])result (10[1])in the most (10[1])common (10[1])application of the Tollens (10[1])test. The simplest compound with this functional group has the formula (10[1]-5[3])CH2O and is a (10[1]-5[1])common (10[1])biological (10[5])preservative. For 10 points, name (10[1])this functional (10[3])group composed of a terminal (10[1])carbonyl group, unlike a (10[3])ketone. (10[12]0[5])■END■