CHE 242 Unit VIII The Structure, Properties, Reactions and Mechanisms of Carboxylic Acids and Their Derivatives CHAPTER TWENTY-FIVE Terrence P. Sherlock Burlington County College 2004
Chapter 252 Examples of Lipids =>
Chapter 253 Waxes Esters of long-chain fatty acids with long-chain alcohols. Spermaceti is found in the head of the sperm whale and is probably used to control buoyancy. Most natural waxes are protective coats for plants’ leaves, insects’ exoskeleton, mammals’ fur, and birds’ feathers. =>
Chapter 254 Triglycerides Fatty acid esters of glycerol. Fats Solid at room temperature Most are derived from mammals Oils Liquid at room temperature Most are derived from plants or cold- blooded animals. =>
Chapter 255 Fatty Acids Unbranched carboxylic acids with carbons. Most contain an even number of carbons because they are built from acetic acid units. Melting points increase with increasing molecular weights. Unsaturation greatly lowers the melting point. =>
Chapter 256 Melting Points A cis double bond bends the molecule so it cannot pack efficiently. A trans double bond has less effect. =>
Chapter 257 Fats and Oils Most fats have saturated fatty acids. Most oils have unsaturated fatty acids. =>
Chapter 258 Saponification “Soap-making” Base-catalyzed hydrolysis of ester linkages in fats and oils. A soap =>
Chapter 259 Soap Structure =>
Chapter 2510 Grease in Soap Solution =>
Chapter 2511 Detergents =>
Chapter 2512 Steroids Polycyclic, usually all trans. Common structural features: =O or -OH at C3 Side chain at C17 Double bond from C5 to either C4 or C6. =>
Chapter 2513 A-B Ring Junction May be cis, but usually is trans. =>
Chapter 2514 Cholesterol Common biological intermediate. Probably a precursor to other steroids. Side chain at C17 and double bond C5-C6. =>
Chapter 2515 Sex Hormones Female hormone has an aromatic ring and one less methyl group than the male hormone. Testosterone is converted to estradiol in the ovaries. =>
Chapter 2516 POWER POINT IMAGES FROM “ORGANIC CHEMISTRY, 5 TH EDITION” L.G. WADE ALL MATERIALS USED WITH PERMISSION OF AUTHOR PRESENTATION ADAPTED FOR BURLINGTON COUNTY COLLEGE ORGANIC CHEMISTRY COURSE BY: ANNALICIA POEHLER STEFANIE LAYMAN CALY MARTIN