Methylene bridge
In
repeating unit in the skeleton of the unbranched alkanes
.
A methylene bridge can also act as a
aluminum in Tebbe's reagent.[1]
A methylene bridge is often called a methylene group or simply methylene, as in "methylene chloride" (dichloromethane CH
2Cl
2). As a bridge in other compounds, for example in cyclic compounds, it is given the name methano. However, the term methylidene group (not to be confused with the term methylene group, nor the carbene methylidene) properly applies to the CH
2 group when it is connected to the rest of the molecule by a double bond (=CH2), giving it chemical properties very distinct from those of a bridging CH
2 group.
Reactions
Compounds possessing a methylene bridge located between two strong
carbanions, which are often used in organic synthesis. Examples include the Knoevenagel condensation and the malonic ester synthesis.[3]
Examples
Examples of compounds which contain methylene bridges include:
See also
- Methyl group
- Methylene group
- Methyne
References
- ^ W. A. Herrmann (1982), "The methylene bridge". In Advances in Organometallic Chemistry, volume 20, pages 195-197.
- ^ "Active methylene compound".
- ISBN 0-8053-4501-9.