Last Lecture Overview1 Overview Lecture: Carboxylic Acids, Esters, Amines & Amides

Last Lecture Overview2 Carboxylic Acids have the structure R-C-O-H, also written as:. RCOOH and RCO 2 H. -COOH is called the carboxyl group. O

Last Lecture Overview3 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 Overview4 Example CH 3 -CH 2 -CH-CH 2 -COH O OH hydroxypentanoic acid

Last Lecture Overview5 Carboxylic Acids are weak acids: They are H + donors, but not completely ionized in water. H-A H + + A – K a << 1, which means that. At equilibrium mostly HA present.

Last Lecture Overview6 Amines are organic bases derived from ammonia (NH 3 ). In amines a carbon group replaces an H in NH 3.

Last Lecture Overview7 Ammonia = H-N-H H R-NH 2 R-NH-R’ R-N-R’ R” 1° Amine 2° Amine 3° Amine

Last Lecture Overview8 Simple Naming of Amines Name the alkyl groups bonded to N, followed by the word “amine” : CH 3 CH 2 -NH-CH 3 is named ethylmethylamine

Last Lecture Overview9 Amines * are Hydrogen-bond donors and H-bond acceptors * are weak bases

Last Lecture Overview10 Amines are bases because they are H + acceptors. All amines are weak bases like NH 3. R-NH 2 + H 2 O R-NH HO - K << 1

Last Lecture Overview11 Esters and Amides are obtained by replacing the OH group of RCOOH. R-C-OH O R-C-OR’ R-C-N OO R’ R” Ester Amide

Last Lecture Overview12 The OH of RCOOH can be replaced chemically in several steps in the lab or by enzymes. More important than how: 1) Esters come from RCOOH + ROH (an alcohol); while 2) Amides come from RCOOH + Amine or Ammonia.

Last Lecture Overview13 CH 3 CH 2 C-OH + H-O-CH 2 CHCH 3 O CH 3 - H 2 O by enzyme or in lab CH 3 CH 2 C-O-CH 2 CHCH 3 O CH 3 Example of Ester Synthesis

Last Lecture Overview14 Thus, the basic equation is Carboxylic acid + alcohol  ester + water

Last Lecture Overview15 Example of Amide Synthesis CH 3 CH 2 C-OH + H-NH-CH 3 O - H 2 O by enzyme or in lab CH 3 CH 2 C-NH-CH 3 O

Last Lecture Overview16 Again, the basic equation is Carboxylic acid + amine or NH 3 amide + water

Last Lecture Overview17 Esters and Amides are hydrolyzed (broken down by H 2 O in H + or HO - ). Ester + H 2 O  Carboxylic acid + Alcohol Amide + H 2 O  Carboxylic acid + Amine (or ammonia)

Last Lecture Overview18 Hydrolysis Examples C-OCH 2 CH 2 CH 3 O H 2 O with enzyme or H + or HO - COH + HOCH 2 CH 2 CH 3 O Ester carboxylic acid alcohol

Last Lecture Overview19 Hydrolysis Example 2 CH 3 C-NH- O Amide H 2 O with enzyme or H + or HO - CH 3 C-OH + H 2 N- O carboxylic acid amine

Last Lecture Overview20 That’s All Folks The End §