FINAL EXAM - Major Part 3 (12)

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1 NAME (print) Fdfy- CHEM 34 ~ eu c (12) Signature L Id- 2 (22) I I AJ ~.A.,.,a, Soc. Sec. No. FINAL EXAM - Major Part 3 (12) No Books! No Notes! No Calculators! MODELS ALLOWED EXAM HAS FIVE PAGES; 72 total points; Time: 80 Minutes 4 (10) Structures may be drawn using any standard convention used in class 5 (16) which is appropriate to the structure. Use extra sheet at back or reverse of page for additions and corrections. Mark on problem when you do so. SHOW PICTURE ID TO PROCTOR WHEN YOU HAND IN EXAM TOTAL (72) Character- and ldentiflcatlon (12 pointsl a) The main functional we have studied this semester which are found in naturally occurring substances include alkenes, alcohols, ethers, phenols, amines, aldehydes, ketones, carboxylic acids, esters, and amides. What is the main functional group in butter? What is the common functional group in alkaloids? What is the repeating functional group in insulin? What functional group do muscone and civetone have in common? b) A hexapeptide obtained by enzymic digestion of myoglobin contains 2 serines (abbreviation Ser), 1 alanine (Ala), 1 glycine (Gly), 1 methionine (Met), and 1 valine (Val). Partial acid hydrolysis of this peptide gives four smaller peptides: Gly-Ser-Met, Val-Ser, Ala-Gly, and Met-Val. What is the amino acid seauence of this peptide? Circle the amino acid with %the free amino aroud. c) Assume you have unlabelled samples of J-M. They are easily distinauished bv taste. Sweet, sour, salty, bitter, and none are standard tastes. Match the correct Mste t~ each GQfmQw-

2 f-70 k Chem 34 Final Exam Page 2 Name 2. Reactions and Svntheses ( ~ointsl, Qraw the carbon containi~g products for reactions a-f. catalyst + CHI-CH2-MgBr acidify then! d) CH3- -CH3 + CH3CH20H I,+ 3 catalyst excess ( two products ) then f) CH -CH-CH LilllH4 acidif; CH3 ( two products ) Write equations to show how each of the following conversions can be carried out. The conversions will require more than one step.

3 Chem 34 Final Exam Page 3 Name 3. Products and Properties (1 2 points?. a) All of the compounds A-F have approximately the same molecular weight. Which among A-F has the highest boiling point? Which among A-F is the least soluble in water? Which among A-F is the most easily oxidized? Which among A-F is the most acidic? Which among A-F is the most easily hydrolyzed in aqueous base? b) Consider the compounds J-T. HC-OH Which among J-T is a female sex hormone? Which among J-T is the aroma constituent of bananas? Which among J-T is a drug used to treat malaria? LI Which among J-T is a sugar? Which among J-T an analgesic (painkiller)? Which among J-T is the polymer in PVC plumbing pipe? n n u Which among J-T is a refrigerant?

4 k Chem 34 Final Exam Page 4 Name 4. Puttina It All Toaether with Lessons from the Past ( - ~oints). a) What is a spap and how does it work to clean dirt from clothing? b) What is the name of the repeating unit in both starch and cellulose? What is the main difference between these two polymers? c) We have used the term "resonance" to explain many differences in reactivity and physical properties this semester In the boxes, draw another resonance structure of each of the following compounds which helps explain its exceptional stability. CH3 n d) The addition of methanol dramatically increases the octane rating of gasoline. However, a modern car will travel further on a gallon of gasoline than on a gallon of a mixture of 90% gasoline and 10% methanol. m? (Hint: Obese people should not eat fried foods.) e) One compound named monosodium glutamate (see A) is the main flavor enhancer in oriental foods. However, another compound with the same name has negligible flavor enhancing properties. Ex~lain how this can be true.

5 6 x 4 Chem 34 Final Exam Page 5 Name 5. Mechanisms ( ~oints). a) Draw the correct mechanisms for the two reactions which follow: b) In the reactions which follow, reactants are to the 'left and products to the right. of these reactions has no intermediates (reactants converted to products in one step). For this reaction, write no intermediate in the brackets. For the other two reactions, draw the structure of the first in the brackets. If an intermediate is a resonance hybrid, include both contributing canonical structures. \ N-C% c) One of the products drawn to,the right of each of the equations below is a major or the only product of each reaction in its correct stereochemistry (not necessarily in its best conformation). For each reaction, circle the structure corre~ppndina to this major product CH /H 3C;C H' \CH~ + - c Hq 4.&r Pr c 43 M =% ;;%,ar 3.A; 3 I I H =*3 cfi3 8,

6 5t- E Y [, ~ Chem 34 Final Exam Page 2 Name 0 2. Reactions and Svntheses '. ~oints). Draw the carbon containing products for reactions a-f. 0 CH3 I, a) CH~-?H-CH~-C-H + Cr03 + CH3 0 + ch3-bii-ch2-~i then, acidify ( two products ) Q + CI2 ~0~13 / catalyst ( two products) Write equations to show how each of the following conversions can be carried out. The conversions will require more than one step.

7 &f- f 3- I, Chem34 FinalExam Page 3 Name 0 3. Products and Properties f Doints). a) 'The compounds A-E all have approximately the same molecular weight. O 1 ih3 O CH3-fH2 CH3-CH2-C-NH-CH3 CH3-CH2-C-0-CH3 CH3-CH2-!-~H2-~~3 CH3-C-N-CH3 CH3-CH2-CH-CH3 Which among A-E has the highest boiling point? Which among A-E has the lowest boiling point? Which aniong A-E is the least soluble in water? Which aniong A-E is the most easily hydrolyzed by aquegus base? b) Circle the substance named below which is a disaccharide. Amylose Cellulose Sucrose Fructose Glycogen Circle the compound named below which is an unlikely component of a perfume. Ethyl propanoate Muscone Water Butanoic acid Methyl benzoate What is the name of the saccharide in honey? What is the common (supermarket) name of a 5% solution of acetic acid in water? c) By addinq water, starch can be se~arated into a water soluble fraction called amylose and a water-insol uble fractio;~ called amylopectin. There are two big differences between the structures of amyl ose and amyl opecti n. What are they? d) Name two hormones made in the cell from chol ester01. e) What is the structural difference between (words okay): starch and cell ul ose? cotton and rayon? f) What is the common scientific name of "blood sugar"?

8 Ed- &h,ol Chem 31 Final Exam Page 4 Name 8 4. Puttina It All Toaether with Lessons from the Past - points). a) J&!& do bile salts work to facilitate (= help accomplish) the passage of fat through the intestinal wall into the bloodstream. b) Vulcanization is an example of crosslinking between polymer chains. Give two other kinds of exam~les of crosslinking between polymer chains. d) Whv are there more calories in a pound of than there are in a pound of suga? - Note that a typical fat has the empirical formula C1 H200 1 while sugar has the empirical formula CI H201. e) Why does an amide (for example A) have a longer carbon to oxygen bond than an ester (for example B).

9 I Ed, &,p e Chem34 Final Exam Page 5 Name 5. Mechanisms ( - 3ointsL a) Draw the correct mechanisms for the two reactions which follow: 0 b) In the reactions which follow, reactants are to the left and products to the right. One of these reactions has no intermediates (reactants converted to products in one step). For this reaction, write no intermediate in the brackets. For the other two reactions, draw the structure of the first intermediate in the brackets. If an intermediate is a resonance hybrid, include both contributing canonical structures. c) One of the products drawn to the right of each of the equations below is a major or the only product of each reaction - in its correct stereochemistry (not necessarily in its best conformation). For each reaction, circle the structure corresoondina to this maior product "&4, c% Cir3 ;J.s P "A: C H CH 3tZC' 3 \ H2 Pd + P & ; D' D catalyst P 1% C! H, t H, cy cu, :u, - 5% CQ, # <M*CY ycy c H z 4 t ow CUl ; U#~-~-SL, - g C#,-;-SH - cy-c-~ g H c*3 & J &/

10 aminuuq A hexapeptide obtained by enzymic digestion of ribonuclease contains 1 alanine (abbreviation Ala), 2 glycines (Gly), 1 leucine (Leu), 1 serine (Ser), and 1 valine (Val). Partial acid hydrolysis of this peptide gives four smaller peptides: Leu-Gly-Val, Ala-Gly, Ser-Leu, and Qly-Ser. What is the amino acid se- of this peptide? Circle the amino acid with the Assume you have unlabelled samples of J-M. They are easily distinauished bv taste. Sweet, sour, salty, bitter, and none are standard tastes. Match the correct taste to each Assume you have unlabelled samples of J-M. 'They are easily distinguished by smell. Describe the smell of each in enough detail so can be distinguished. 0 + " 11 0 H3N-C~-~-i4b!-~~-~-0- I I CH3-CH2-CH-C-OH I CHI-CH2-(HZ-C-0-CH2-CHI H 2 N 0 CH2 CH, CH, The senses are important aids in identifying organic compounds. What does: feel like? taste like? smell like? look like?