allylgrupper

Allylgrupper refers to the allyl group, a functional group in organic chemistry with the formula CH2=CHCH2-. It is an unsaturated hydrocarbon group, characterized by a double bond adjacent to a methylene group. The allyl group is derived from propene by the removal of one hydrogen atom from the methyl group. This arrangement makes the allyl group quite reactive, particularly at the allylic carbon atom, which is the carbon atom directly bonded to the double bond. The double bond can readily undergo addition reactions, such as halogenation or hydrogenation. The allylic position is also susceptible to substitution reactions due to the stability of the allylic carbocation or radical intermediate. This stability arises from the resonance delocalization of the positive charge or unpaired electron across the double bond. Allyl compounds find applications in various fields, including the synthesis of polymers, pharmaceuticals, and fragrances. For instance, allyl alcohol is a precursor to glycerol, and diallyl phthalate is used in the production of resins. The term "allylic" is also used to describe the position adjacent to a double bond in a molecule, even if the entire allyl group is not present.