Carboxylic Acid Derivatives | Organic Chemistry 2
Properties and Relative Reactivities
H is acidic. The pKa depends on the electronegativity of L
⇒ The lower the electronegativity, the higher the pKa.
Acyl Halide: pKa ~ 16; Carb. Anh.: pKa ~ 20; Ester: pKa ~ 25; Amide: pKa ~ 30.
Chemistry of Acyl Halides
Naming:
The -oic acid ending of the corresponding carboxylic acid is replace by -oyl halide.
('halide' = fluoride, chloride, bromide, iodide)
Formation of Carboxylic Acid, Carboxylic Anhydride, Ester and Amide:
- NuH = HOH ⇒ Carboxylic Acid Formation
- NuH = R'COOH ⇒ Carboxylic Anhydride Formation
- NuH = R'OH ⇒ Ester Formation
- NuH = R'HNH ⇒ Amide Formation
Mechanism: Addition-Elimination
Formation of Ketone:
Mechanism: Addition-Elimination
Formation of Aldehyde:
Mechanism: Addition-Elimination
Chemistry of Esters
Naming:
The alkyl chain R' is named as a substituent.
This is followed by the name of the parent chain (RC) where the -ane of the corresponding alkane is replaced by -oate.
Formation of Carboxylic Acid, Ester and Amide:
- NuH = HOH ⇒ Carboxylic Acid Formation
- NuH = R''OH ⇒ New Ester Formation (Transesterification)
- NuH = R''HNH ⇒ Amide Formation
Mechanism: Addition-Elimination
Formation of Alcohol:
Mechanism: Addition-Elimination
Mechanism: Addition-Elimination
Formation of Aldehyde:
Chemistry of Carboxylic Anhydrides
Naming:
Add the term anhydride to the carboxylic acid name.
Formation of Carboxylic Acid, Ester and Amide:
- NuH = HOH ⇒ Carboxylic Acid Formation
- NuH = R'OH ⇒ Ester Formation
- NuH = R'HNH ⇒ Amide Formation
Mechanism: Addition-Elimination
Chemistry of Amides
Naming:
The -ane ending of the corresponding alkane is replace by -amide.
Substituents on the nitrogen are indicated by the prefix N- or N,N- (if two similar groups).
Formation of Carboxylique Acid:
Mechanism: Addition-Elimination
Formation of Amine:
Formation of Aldehyde:
