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Announcements & Agenda (04/04/07)

Announcements & Agenda (04/04/07). Will start with quiz today Review session today @ 3pm (same place) Today Amides (13.5) Sugars! Section 14.1-14.3 Carbohydrates Monosaccharides Cyclic Monosaccharides (?). Last Time: Hydrolysis of Esters.

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Announcements & Agenda (04/04/07)

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  1. Announcements& Agenda(04/04/07) • Will start with quiz today • Review session today @ 3pm (same place) • Today • Amides (13.5) • Sugars! Section 14.1-14.3 • Carbohydrates • Monosaccharides • Cyclic Monosaccharides (?)

  2. Last Time: Hydrolysis of Esters • an ester reacts with water to produce a carboxylic acid and an alcohol. • an acid catalyst is required. O  H+ H—C—O—CH2—CH3 +H2O O  H—C—OH +H—O—CH2—CH3 Base Hydroylsis forms an alcohol plus the salt of a carboxylic acid!

  3. 0 What acid and alcohol make the following ester? • Ethanol (2C) and acetic acid (2C) • Propanol (3C) & acetic acid (2C) • Ethanol (2C) & propionic acid (3C) • Methanol (1C) & propionic acid (3C)

  4. Last Time: Base Hydrolysis of Triglycerides Make Soaps

  5. Last Time: Amines (Derivatives of NH3) Typically 3 kinds: • primary (1°) amines: 1 carbon group is bonded to N • secondary (2°) amines: 2 carbon groups bonded to N • tertiary (3°) amines: 3 carbon groups bonded to N. Can H-bond like alcohols, although N is not as polar • decent BPs & solubility in water Act as weak bases: CH3—NH2 + H2O CH3—NH3+ + OH– • Useful properties of amine salts: • solids at RT, very soluble in body fluids (ideal for drug molecules, and salts don’t stink 

  6. N C H 3 Last Time: Alkaloids • physiologically active nitrogen-containing compounds. • often addictive. nicotine

  7. Morphine and Codeine • alkaloids. • obtained from the oriental poppy plant. • used as painkillers. • modified to make heroin.

  8. Chocolate • Chocolate is found in cocoa beans

  9. Last Time: Amides (13.5) made from… Amine + Carboxylic Acid Amides are produced • by reacting a carboxylic acid with ammonia or an amine (1° or 2°). • using heat. O O  Heat  CH3—C—OH +NH3 CH3—C—NH2+ H2O O O  Heat  CH3—C—OH + CH3—NH2 CH3—C—NH—CH3+ H2O

  10. Some Amides in Health and Medicine

  11. Physical Properties of Amides SIMILAR TO AMINES… • primary (−NH2) or secondary (−NH−) amides form hydrogen bonds. • primary have higher mp’s than secondary. • tertiary (no H on N) do not form hydrogen bonds & have lower melting points. • all form hydrogen bonds with water. • with 1-5 carbon atoms are soluble in water.

  12. Hydrolysis of AmidesIMPORTANT TO KNOW Amides undergo • Acid hydrolysis to produce a carboxylic acid and an ammonium salt. • Base hydrolysisto produce the salt of a carboxylic acid and an amine or ammonia. • REACTIONS LOOK SIMILAR TO THOSE OF ESTERS!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

  13. Hydrolysis Reactions acid hydrolysis O || O CH3—C—OH + NH4+Cl– ||HCl+ H2O CH3—C—NH2 NaOHO || CH3—C—O– Na+ + NH3 base hydrolysis

  14. Ch 14 Carbohydrates • a major source of energy from our diet • composed of C, H, & O • also known as saccharides, which means “sugars.”

  15. Practice Problems (Ch 14) 14.05, 14.07, 14.09, 14.13, 14.15, 14.19, 14.21, 14.23, 14.25, 14.27, 14.29, 14.31, 14.33, 14.35, 14.37, 14.39, 14.41, 14.47, 14.49, 14.51, 14.53, 14.57, 14.59

  16. Carbohydrates • produced by photosynthesis in plants • Example: glucose synthesized in plants from CO2, H2O, and energy from the sun. • are oxidized in living cells to produce CO2, H2O, and energy.

  17. Types of Carbohydrates • Monosaccharides: simplest carbohydrates. • Disaccharides: consist of two monosaccharides. • Polysaccharides: contain many monosaccharides.

  18. Monosaccharides • typically 3-6 carbon atoms • have a C=O group (aldehyde or ketone) • aldoses • ketoses • several hydroxyl groups

  19. Aldoses O ║ C─H aldose │ H─ C─OH │ H─ C─OH │ CH2OH Erythose • monosaccharides with an aldehyde group… • …and many hydroxyl groups. triose (3C atoms) tetrose (4C atoms) pentose (5C atoms) hexose (6C atoms)

  20. Ketoses CH2OH │ C=O ketose │ H─ C─OH │ H─ C─OH │ H─C─OH │ CH2OH • monosaccharides with a ketone group… • …and many hydroxyl groups. Fructose, a ketohexose

  21. Fischer Projections • also used to represent carbohydrates. • places the most oxidized group at the top. • shows chiral carbons as the intersection of vertical and horizontal lines.

  22. D & L Notations: Know This Now… In a Fischer projection, the −OH group on the • chiral carbon farthest from the carbonyl group determines an L or D isomer. • left = Lfor the L-form. • right = Dfor the D-form. (MOST COMMON IN NATURE!)

  23. Learning Check Identify each as the D or L isomer. A. B. C. __-Ribose __- Threose __- Fructose L D L

  24. D-Glucose • found in fruits, corn syrup, and honey • an aldohexose with the formula C6H12O6 • known as blood sugar in the body • the monosaccharide in polymers of starch, cellulose, and glycogen

  25. Blood Glucose Level In the body, • normal blood: [glucose] = 70-90 mg/dL. • a glucose tolerance test measures blood glucose for several hours after ingesting glucose.

  26. D-Fructose • is a ketohexose C6H12O6 • is the sweetest carbohydrate • found in fruit juices and honey • converts to glucose in the body

  27. D-Galactose • is an aldohexose C6H12O6. • not found free in nature. • is obtained from lactose, a disaccharide. • has a similar structure to glucose except for the –OH on C4 Which C is C4???

  28. Cyclic Structures (14.3) • prevalent form of monosaccharides with 5 or 6 carbon atoms • form when the hydroxyl group on C-5 reacts with the aldehyde group or ketone group • Orgo-Chem reaction not previously mentioned: “C=O” + ROH → hemiacetal

  29. Drawing Cyclic Structures: Practice! Example: Glucose STEP 1 Number the carbon chain and turn clockwise to form a linear open chain. 1 2 3 4 5 6 6 5 4 3 2 1

  30. Cyclic Structure for Glucose STEP 2 Fold into a hexagon. • Bond the C5 –O– to C1. • Place the C6 group above the ring. • Write the –OH groups on C2 & C4 below the ring (These are the C atoms that pointed down from Step 1). • Write the –OH group on C3 above the ring. • Write a new –OH on C1. 6 5 4 1 3 2

  31. Cyclic Structure for Glucose • STEP 3 Write the new –OH on C1 • down for the  form. • up for the  form.   -D-Glucose-D-Glucose

  32. Summary of the Formation of Cyclic Glucose

  33. C H O H C H O H C H O H 2 2 2 H O O O O H O C O H O H O H H O H O H O H O H O H O H O H Mutarotation • cyclic structures open and close. • -D-glucose converts to β-D-glucose & vice versa. • at any time, only a small amount of open chain forms. -D-glucose D-glucose (open) β-D-glucose (36%) (trace) (64%)

  34. C H O H 2 C H O H C H O H C H O H O H 2 2 O O C O 2 H O C H O H O H H C O H O H C H O H 2 H C O H O H O H C H O H 2 Cyclic Structure of Fructose • is a ketohexose. • reacts the -OH on C-5 with the C=O on C-2 α-D-fructose D-fructose -D-fructose

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