Allyyliryhmiä

Allyyliryhmiä, also known as allyl groups, are organic functional groups with the chemical formula –CH₂CH=CH₂. They consist of a methylene group (–CH₂) attached to a vinyl group (–CH=CH₂). This structure is derived from propene (CH₃CH=CH₂) by the removal of one hydrogen atom from the methyl group. The double bond in the vinyl portion makes the allyl group unsaturated and reactive, participating in various chemical reactions like addition and polymerization.

Allyl compounds are prevalent in nature and have significant industrial applications. For instance, allyl alcohol (CH₂=CHCH₂OH) is a key intermediate in the synthesis of glycerol, pharmaceuticals, and plastics. Allyl chloride (CH₂=CHCH₂Cl) is another important precursor, used in the production of epichlorohydrin, which is essential for making epoxy resins. Many natural products, such as flavors and fragrances like vanillin, contain allyl moieties. The characteristic reactivity of the allyl group stems from the allylic position, which is adjacent to the double bond. This position is susceptible to substitution reactions, often proceeding through resonance-stabilized allylic carbocations, carbanions, or radicals. The presence of the double bond also allows for electrophilic addition reactions and participation in cycloaddition and polymerization processes.