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Overview Lecture: Carboxylic Acids, Esters, Amines & Amides. Carboxylic Acids have the structure R-C-O-H , also written as: RCOOH and RCO 2 H . -COOH is called the carboxyl group. O. Nomenclature of RCOOH : 1. Find the longest chain that includes COOH.
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Overview Lecture: Carboxylic Acids, Esters, Amines & Amides Last Lecture Overview
Carboxylic Acids have the structure R-C-O-H, also written as: RCOOH and RCO2H. -COOH is called the carboxyl group. O Last Lecture Overview
Nomenclature of RCOOH: 1. Find the longest chain that includes COOH. 2. Parent name becomes alkane + oic acid. 3. C of COOH becomes #1. 4. COOH more important than other functional groups. Last Lecture Overview
Example CH3-CH2-CH-CH2-COH O 3 1 2 5 4 OH 3-hydroxypentanoic acid Last Lecture Overview
Carboxylic Acids are weak acids: They are H+ donors, but not completely ionized in water. H-AH+ + A– Ka << 1, which means that At equilibrium mostly HA present. Last Lecture Overview
Amines are organic bases derived from ammonia (NH3). In amines a carbon group replaces an H in NH3. Last Lecture Overview
Ammonia = H-N-H H R-N-R’ R” R-NH2 1° Amine 3° Amine R-NH-R’ 2° Amine Last Lecture Overview
Simple Naming of Amines Name the alkyl groups bonded to N, followed by the word “amine” : CH3CH2-NH-CH3 is named ethylmethylamine Last Lecture Overview
Amines * are Hydrogen-bond donors and H-bond acceptors * are weak bases Last Lecture Overview
Amines are bases because they are H+ acceptors. All amines are weak bases like NH3. R-NH2 + H2O R-NH3+ + HO - K << 1 Last Lecture Overview
Esters and Amides are obtained by replacing the OH group of RCOOH. O R-C-OH O O R’ R-C-OR’ R-C-N R” Ester Amide Last Lecture Overview
The OH of RCOOH can be replaced chemically in several steps in the lab or by enzymes. • More important than how: • Esters come from RCOOH + ROH (an alcohol); while • Amides come from RCOOH + Amine or Ammonia. Last Lecture Overview
Example of Ester Synthesis CH3 O CH3CH2C-OH + H-O-CH2CHCH3 -H2O by enzyme or in lab O CH3 CH3CH2C-O-CH2CHCH3 Last Lecture Overview
Thus, the basic equation is Carboxylic acid + alcohol ester + water Last Lecture Overview
Example of Amide Synthesis O CH3CH2C-OH + H-NH-CH3 -H2O by enzyme or in lab O CH3CH2C-NH-CH3 Last Lecture Overview
Again, the basic equation is Carboxylic acid + amine or NH3 amide + water Last Lecture Overview
Esters and Amides are hydrolyzed (broken down by H2O in H+ or HO-). Ester + H2O Carboxylic acid + Alcohol Amide + H2O Carboxylic acid + Amine (or ammonia) Last Lecture Overview
Hydrolysis Examples O Ester C-OCH2CH2CH3 H2O with enzyme or H+ or HO- O COH + HOCH2CH2CH3 carboxylic acid alcohol Last Lecture Overview
Hydrolysis Example 2 O Amide CH3C-NH- H2O with enzyme or H+ or HO- O CH3C-OH + H2N- carboxylic acid amine Last Lecture Overview
That’s All Folks The End § Last Lecture Overview