allylic substitution reaction

https://doi.org/10.1351/goldbook.A00247
A
substitution reaction
occurring at position 1/ of an
allylic
system, the double bond being between positions 2/ and 3/. The incoming group may be attached to the same atom 1/ as the
leaving group
, or the incoming group becomes attached at the relative position 3/, with movement of the double bond from 2/3 to 1/2. For example:
(written as a
transformation
).
Source:
PAC, 1994, 66, 1077. (Glossary of terms used in physical organic chemistry (IUPAC Recommendations 1994)) on page 1082 [Terms] [Paper]