Francais | English | Espanõl

From Wikipedia, the free encyclopedia

This article is about chemical reactions resulting in the loss of water from a molecule. For the removal of water from solvents and reagents, see desiccation.

In chemistry, a dehydration reaction is a chemical reaction that involves the loss of water from the reacting molecule. Dehydration reactions are a subset of elimination reactions. Because the hydroxyl group (-OH) is a poor leaving group, having an Brønsted acid catalyst often helps by protonating the hydroxyl group to give the better leaving group, -OH₂⁺.

In organic synthesis, there are many examples of dehydration reactions:

• Conversion of alcohols to ethers

2 R-OH → R-O-R + H₂O

• Conversion of alcohols to alkenes

R-CH₂-CHOH-R → R-CH=CH-R + H₂O

• Conversion of carboxylic acids to acid anhydrides

2 RCO₂H → (RCO)₂O + H₂O

• Conversion of amides to nitriles

RCONH₂ → R-CN + H₂O

[edit] See also

• Hydration reactionde:Dehydrierung

ja:脱水反応 nl:Dehydratie (chemie) ru:Дегидратация