<unk> s are chemical reactions involving<unk>  compounds. The basic<unk>  chemistry reaction types are addition reactions, elimination reactions, substitution reactions, pericyclic reactions, rearrangement reactions and redox reactions. In<unk>  synthesis,<unk> s are used in the construction of new<unk>  molecules. The production of many man-made chemicals such as drugs, plastics, food additives, fabrics depend on<unk> s.
The oldest<unk> s are combustion of<unk>  fuels and saponification of fats to make soap. Modern<unk>  chemistry starts with the Wöhler synthesis in 1828. In the history of the Nobel Prize in Chemistry awards have been given for the invention of specific<unk> s such as the Grignard reaction in 1912, the Diels-Alder reaction in 1950, the Wittig reaction in 1979 and olefin metathesis in 2005.
Organic reaction
Organic redox reaction
Condensation reaction
Exothermic reaction
Isothermal process
Free radical reaction
Chemical modification
Hydrolysis