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[4] [5] The amide group is called a peptide bond when it is part of the main chain of a protein, and an isopeptide bond when it occurs in a side chain, as in asparagine and glutamine. It can be viewed as a derivative of a carboxylic acid ( R−C(=O)−OH ) with the hydroxyl group ( −OH ) replaced by an amine group ( −NR′R″ ); or ...
Sphingomyelins have a phosphocholine or phosphoethanolamine molecule with an ester linkage to the 1-hydroxy group of a ceramide. Glycosphingolipids are ceramides with one or more sugar residues joined in a β-glycosidic linkage at the 1-hydroxyl position (see image). Cerebrosides have a single glucose or galactose at the 1-hydroxy position.
The final step in the reduction of carboxylic acids and esters is hydrolysis of the aluminium alcoxide. [8] Esters (and amides) are more easily reduced than the parent carboxylic acids. Their reduction affords alcohols and amines, respectively. [9] The idealized equation for the reduction of an ester by lithium aluminium hydride is:
An ester of a carboxylic acid.R stands for any group (typically hydrogen or organyl) and R ′ stands for any organyl group.. In chemistry, an ester is a compound derived from an acid (organic or inorganic) in which the hydrogen atom (H) of at least one acidic hydroxyl group (−OH) of that acid is replaced by an organyl group (R ′). [1]
Acid–base-catalysed hydrolyses are very common; one example is the hydrolysis of amides or esters. Their hydrolysis occurs when the nucleophile (a nucleus-seeking agent, e.g., water or hydroxyl ion) attacks the carbon of the carbonyl group of the ester or amide. In an aqueous base, hydroxyl ions are better nucleophiles than polar molecules ...
The two major resonance forms of an amide. Another factor that plays a role in determining the reactivity of acyl compounds is resonance. Amides exhibit two main resonance forms. Both are major contributors to the overall structure, so much so that the amide bond between the carbonyl carbon and the amide nitrogen has significant double bond ...
Structurally, amino esters consist of three molecular components: a lipophilic part (ester); an intermediate aliphatic chain; a hydrophilic part (amine); The chemical linkage between the lipophilic part and the intermediate chain can be of the amide-type or the ester-type, and is the general basis for the current classification of local anesthetics.
In organic chemistry, an ortho ester is a functional group containing three alkoxy groups attached to one carbon atom, i.e. with the general formula RC(OR') 3. Orthoesters may be considered as products of exhaustive alkylation of unstable orthocarboxylic acids and it is from these that the name 'ortho ester' is derived.