ABSTRACT
Addition reactions An addition reaction is said to have occurred when a molecule has combined with another, without the loss of any part (atom or groups of atoms) of either molecule. There are two general classes of addition reaction that may be considered, nucleophilic and electrophilic addition (Section I1). For either type of addition reaction to occur one or more units of unsaturation must be present in the molecule being added to. Consequently, addition reactions are only possible with, for example, alkenes, alkynes, aldehydes, and ketones. Addition reactions are not generally feasible with aromatic compounds as they would result in the loss of aromaticity, a stabilizing force (Section K1).
