Allyl is a hydrocarbon radical derived from propylene , in which a hydrogen atom is removed from the third carbon atom . The allyl group is an organic substituent, part of a chemical compound that has the form CH 2 = CH — CH 2 —R. Compounds with an allyl group are often found naturally in plants. Allyl got its name from the Latin name for garlic - Allium sativum . Examples of compounds which include allyl - allyl alcohol CH 2 = CH-CH 2 -OH, allyl chloride CH 2 = CH-CH 2 -Cl.
Ways to get
Allyl can be introduced by various reactions, for example, the Wurz reaction :
- C 6 H 5 Br + CH 2 = CH-CH 2 -Br + 2Na → C 6 H 5 -CH 2 -CH = CH 2 + 2NaBr
Or reaction with Grignard reagent :
- CH 3 MgCl + CH 2 = CH-CH 2 -Cl → CH 2 = CH-CH 2 -CH 3 + MgCl 2
Allyl halides can be prepared by a substitution reaction involving propylene . (The reaction takes place at a temperature of 400-500 degrees Celsius, in the gas phase, at a low concentration of halogen)
- CH 2 = CH-CH 3 + Cl 2 → CH 2 = CH-CH 2 -Cl + HCl
Chemical Properties
Compounds with an allyl group are characterized by all the properties of alkenes .
See also
- Allyl alcohol
- Isoprene
- Propylene
- Alkenes
- Hydrocarbon radical