CHE-310 Organic Chemistry I

1 CHE-310 Organic Chemistry I

Instructor: Dr. James L. Lyle Office: NSM-D-323 Phone: (310) 243-3388; 243-3376 Office Hours: Will be announced in class; open door policy e-mail: [email protected]

1. Grading: Daily exams = 100 4 exams @ 100 pts = 400 final exam = 100 homework required 600

Letter grades will be assigned on the following basis. Grades are not curved. A = 100-93%, A- = 92-90%, B+ = 89-87%, B = 86-83%, B- = 82-80%, C+ = 79-77%, C = 76-73%, C- = 72-70%, D+ = 69-67%, D = 66-60%, F = 59-0%

2. Required Texts: Organic Chemistry, 6th Ed., Morrison & Boyd. Study Guide for ... Molecular Model Kit

3. Exams. Daily exams will be given at the beginning of most lectures. No make up exams will be given, but the two lowest will be dropped. Attendance is expected. If you miss a daily exam it will count toward one of the two dropped exams. For scheduled hourly exams, no make up exams will be given. You must take the exams on the dates and times as scheduled.

4. Final exam. The final exam will be comprehensive.

5. Homework. Daily homework will be assigned. It is due at the beginning of the following lecture period. Penalty points will be assigned for missing or late homework.

6. Prerequisites.

The prerequisite for this course is completion of both semesters of General Chemistry. A co-requisite is enrolment in CHE-311. 2

7. Office Hours. The instructor is available at any time outside of class for questions, etc. Do not hesitate to seek help if you need it.

8. Cheating. Don't do it! At best you will receive a failing grade and be put on academic probation, at worst you will be expelled from the university. Review the University Catalog statement on Academic Integrity!

9. Course goals, objectives and requirements are covered in the rest of this syllabus. 3 CHE-310 TENTATIVE SCHEDULE Fall '03

Meeting Date Chapt. Topic 1. 8/25 1 Introduction/Basic Principles 2. 8/27 1 Basic Principles 3. 8/29 1 Basic Prinicples 9/1 no class 4. 9/3 2 Methane 5. 9/5 2 Methane 6. 9/8 2 Methane/Alkanes 7. 9/10 3 Alkanes 8. 9/12 3 Alkanes 9. 9/15 3 Alkanes 10. 9/17 *** EXAM I *** 11. 9/19 4 Stereochemistry 12. 9/22 4 Stereochemistry 13. 9/24 4 Stereochemistry 14. 9/26 5 Alkyl Halides 15. 9/29 5 Alkyl Halides 16. 10/1 5/7 Alkyl Halides 17. 10/3 6 Alcohols 18. 10/6 6 Alcohols/Ethers 19. 10/8 6 Ethers 20. 10/10 *** EXAM II *** 21. 10/13 8 Alkenes, synthesis 22. 10/15 8 Alkenes, synthesis 23. 10/17 9 Alkenes, reactions 24. 10/20 9 Alkenes, reactions 25. 10/22 9 Alkenes, reactions 26. 10/24 9 Alkenes, reactions 27. 10/27 10 Stereochemistry 28. 10/29 11 Dienes 29. 11/31 11 Dienes 30. 11/3 12 Alkynes 31. 11/5 *** EXAM III *** 32. 11/7 13 Alicyclics 33. 11/10 13 Alicyclics 34. 11/12 13 Epoxides 35. 11/14 14 Aromatic Hydrocarbons/Benzene 36. 11/17 15 Electrophilic Aromatic Substitution 37. 11/19 15 Electrophilic Aromatic Substitution 38. 11/21 15 Electrophilic Aromatic Substitution 39. 11/24 16 Arenes 40. 11/26 16 Arenes 11/27 no class, Thanksgiving holiday 41. 12/1 16 Arenes 42. 12/3 *** EXAM IV *** 4 43. 12/5 TBA 44. TBA *** FINAL EXAM *** 1 CHEM-310 Information re Exam I

In studying for your first exam in this course, you should first go over all of the homework assignments and make sure that you understand them. In fact, you should be able to do any of the assigned homework problems on the exam. This is more difficult than doing the homework when you have access to your notes, etc. One way to prepare would be to redo all of your homework as if it were an exam. Then, pay particular attention to those problems that you cannot do or do not understand. If you have questions about any of the assigned material you should seek help immediately.

- be able to define important terms.

- from atomic numbers be able to give the numbers of protons and electrons in a neutral atom.

- be able to give spectral notations for neutral atoms.

- be able to identify ionic and covalent bonding.

- be able to draw Lewis dot structures for simple molecules.

- state the types of hybrid orbitals used in simple molecules and give their angles.

- know the relative strengths of some simple acids and bases.

- for acid base reactions, be able to predict if a reaction takes place, or if the reaction is given, label the stronger and weaker acids and bases.

- be able to predict which compounds are polar.

- predict the important products of the reactions of methane.

- be able to name alkanes.

- know the mechanism for free radical halogenation of alkanes. You may be asked to propose a similar mechanism for a reaction you have not done!

- be able to calculate enthalpy changes, given bond dissociation energies. 2 - be able to graph P.E. changes and label all parts of the graph.

- be able to estimate Energies of activation and predict which step in a mechanism is rate determining. Know the importance of Eact to the rates of chemical reactions.

- be able to draw hypothetical structures for transition states.

- understand the Hammond Postulate

- draw Newman projections for conformations in alkanes.

- be able to write equations to show how you would synthesize alkanes in the laboratory, given the starting materials.

- be able to predict the organic products of the reactions of alkanes. 3 CHE 310 Information about Exam II

Your second exam will cover the chapters on stereochemistry, alkyl halides, alcohols and ethers. To study for this exam you should go over your homework assignments. It will also help to write your own version of the exam and trade with another student. Try to boil the subject down to the basic principles.

This exam will have a section on stereochemistry. You must be able to correctly specify R/S for stereoisomers (you may bring a model to the exam). You must know the definitions of the terms from this chapter, and understand what is important for each of the types of reactions of chiral molecules that you might encounter.

For alkyl halides, alcohols and ethers, be able to name compounds correctly (nomenclature). Where necessay, be able to specify congiguration in the name.

Know the two new mechanisms that we have learned in these chapters: SN2, SN1. Know which mechanisms go with which reactions under which conditions. Be able to write out all steps in the mechanisms for given reactions and label the RDS.

Be able to predict the organic products of the reactions of alkyl halides, alcohols and ethers. This is where you will be tested on the particulars of a reaction such as rearrangements, stereochemistry, and orientation.

Know how to synthesize any alkyl halide or ether from a given starting material. Some of the methods used in syntheses may also be covered in the part of the exam on reactions or mechanisms.

Pay particular attention to those homework problems that are of the above types. If you have any questions about the material, please do not hesistate to come see me.

J. Lyle 4 CHE 310 Homework # 1

1. Read Chapter 1 of your text.

2. Define the following terms: Organic chemistry, Pauli exclusion principle, Atomic orbital.

3. For each of the following, state how many protons are there in the nucleus? how many eletrons are there in shells about the nucleus? Give the spectral notation (1s22s2...): Na, Cl, Ne, Cl-, Na+, O, O2-, Br, Ar, Br-, I, C.

5. On page 5 of your text: 1.1 (a,b,c,d), 1.2 (a,b,c,d)

CHE 310 Homework # 2

1. Define the following terms: Ionic bond, Covalent bond.

2. What kind of hybridization is used by the central atom in each of the following compounds and what are the approximate bond angles? + + CH4 BF3 BeCl2 NH4 CH3 (CH3)3B BF4-

3. Draw Lewis dot structures to show the bonding in the following covalent compounds:

+ + NH3 H2O H3O NH4 CO2 5

CHE-310 Homework # 3

1. In your text do problems: 1.6 on page 26, 1.9 on page 35, 1.11 (a) page 36, 5 (a thru f).

2. In the following reactions, label the acids and bases involved, and label each as stronger or weaker.

+ H3O + HCO3- ----> H2CO3 + H2O

NaCN + H2O <---- HCN + NaOH

NaCl + HI ----> HCl + NaI

CH3MgBr + H2O ---> CH4 + Mg(OH)Br

3. Define the following terms:Lewis acid, Lewis base,Lowry- Bronsted acid,Lowry-Bronsted base,isomers.

1. Read Chapter 2

2. Predict the important products of the following reactions; if no reaction takes place, write N.R.:

A) CH4 + (xs)O2,flame ---->

o B) 6CH4 + O2, 1500 ---->

o C) CH4 + H2O, 850 ,Ni---->

D) CH4 + Br2,hv ----->

E) CH4 + Cl2 ---->

F) CH4 + (xs)Cl2,heat ---->

3. Name the following compunds, giving two names for each:

CH3I CH2Br2 CHCl3 CBr4 6 4. Write all steps in the free radical substitution mechanism for the chlorination of methane. Label the initiating, propagating, and terminating steps. Label the rate determining step (RDS).

1. Calculate the enthalpy change (delta H) for the following reaction. heat CH4 + Br2 ------> HBr + CH3Br

2. Outline all steps in the mechanism for the above reaction, and calculate the delta H for each step in the mechanism.

3. Draw a graph of the potential energy changes in the second step of the above mechanism. (the graph can be free hand, but should have all parts labeled.)

4. Draw a graph of the P.E. changes in the third step of the mechanism.

5. An alternate mechanism for chlorination of methane was proposed by a student and contained the following two propagating steps:

. . (2) Cl + CH4 ----> CH3Cl + H . . (3) H + Cl2 ----> HCl + Cl

Calculate the delta H for each of the above steps. Why does the chlorination of methane proceed by the mechanism in the text and not by this alternative route? 7

The compound HOCl (hypochlorous acid) reacts with the compound C6H5CH3 (toluene) under the influence of ultraviolet light as shown in the following equation: hv C6H5CH3 + HOCl ------> C6H5CH2Cl + HOH

The bond dissociation energies pertinent to the above system are:

C6H5CH2-H 85; HO-Cl 60; C6H5CH2-Cl 68; H-OH 119 Kcal/mole

1. Calculate the enthalpy change for the reaction.

2. Write a stepwise mechanism for the above reaction and label the initiating and propagating steps. (Take the bond dissociation energy values into account when considering the most likely mechanistic steps.) Write two possible terminating steps.

3. Calculate the enthalpy changes for the steps in your mechanism, where possible.

4. Draw a graph of the potential energy changes for the third step in your mechanism. Label all parts of the graph.

5. Estimate the Energies of Activation for each of the propagating steps in the mechanism.

6. Which of the steps is the RDS (rate determining step)? How do you know?

7. Draw a hypothetical structure for the transition state for step 2 of the mechanism. 8

1. Read Chapter 3.

2. Draw the Newman Projections for the following conformations about the C2-C3 bond in n-butane: anti, gauche, CH3-H eclipsed, and CH3-CH3 eclipsed. Which of these are stable conformations?

3. Name the following structures:

CH3 CH3CH2CH2CH2CH3 CH3CH2CH2CH2

CH3 CH3 CH3 CH3CHCH2CHCH2CH3 CH3CH2CCH3 CH3

CH3 CH3 CH2 CH3 CH3 CH3 CH2 CH3CHCH2CH2CHCH3 CH3CH2CHCH2CHCHCH2CH2 CH2 CH2 CH3

4. Draw all nine isomeric heptanes (C7H16) and name each one.

CHE-310 Homework # 8 page 99 3.9, 3.10,3.11 9 page 121 8, 9 (a,b,c)

1. In your text: p. 103:3.12;3.14 (predict the products and circle the major product. Do not predict the proportions.) p. 121;10 (and circle the major product.)

2. Outline all steps in the mechanism for the bromination of ethane. Label the RDS.

1. Read Chapter 4.

2. Define the following terms: stereochemistry, optical acitivity, dextrorotatory, levorotatory, specific rotation, chirality, chiral center, enantiomers, racemic modification,configurations.

3. 4.3; 4.4; 4.5 (a-d); 4.8; 4.10 (a).

CHE-310 Homework # 11(a)

1. Define the following: diasteromers, meso compound, resolution

2. In your text: 4.12 (a,b,h); 4.13.

CHE-310 Homework # 11(b)

1. In your text: 4.24.

2. For each of the following reaction types, write a sentence or two to indicate the sterochemical importance of that type of reaction, or the basic principle to keep in mind about that type 10 of reaction. a) a reaction of achiral compounds in which a chiral center is generated. b) a reaction of a chiral compound in which no bonds to the chiral center are broken. c) a reaction as in c) where a new chiral center is formed. d) a reaction of a chiral molecule with an optically active reagent. e) a reaction of a chiral molecule in which a bond to the chiral center is broken.

1. Read Chapter 5.

2. In your text: p. 211: 2; 3; 4;

3. Outline all steps in a possible laboratory synthesis of:

a) n-propyl bromide from n-propyl alcohol, TWO WAYS.

b) isopropyl iodide from isopropyl alcohol, THREE WAYS.

In your text: 5.2; p. 212: 5; 6(a).

Predict the product(s) of the following reaction. You must show the stereochemistry of the product(s).

CH3 ¦ SN2 H ---+--- Br + NaOH -----> ¦ CH2CH3

Using "curved arrow formalism", outline all steps in the mechanism for the following reaction and label the RDS.

CH3Br + NaOH -----> CH3OH + NaBr

Draw a hypothetical structure for the transition state of the RDS in the above mechanism. What is the name of this mechanism? 11 12 CHE 310 Homework # 14

Predict the product(s) of the following reaction. Show the stereochemistry of the product(s):

CH3 ¦ SN1 H ---+--- Br + NaOH -----> ¦ CH2CH3

Using "curved arrow formalism", outline all steps in the mechanism for the following reaction and label the RDS.

CH3 CH3 CH3C-Br + dilute NaOH -----> CH3C-OH + NaBr + alkene CH3 CH3

Draw a hypothetical structure for the transition state of the RDS in the above mechanism. What is the name of this mechanism?

In your text: p. 212 8 (a-h); p. 271 4 (i,j);

Complete the following reactions: CH3 CH3CHCHCH3 + HBr -----> OH

CH3CH2CH2CH2OH + HI -----> p. 247 read "About Syntheses" 17 (a,b,d,e,h). 13

Outline all steps in the mechanism(s) for the reactions: Don;t forget to use "curved arrows" to show the movement of electron pairs. Label the RDS. Name each mechanism!

H+ CH3CH2-OH + HCl -----> CH3CH2-Cl + H2O

H+ tert-butyl alcohol + HBr -----> tert-butyl bromide + H2O

Give the structures of the organic products expected for the following reactions:

1. n-butyl alcohol with a) sodium bromide, sulfuric acid b) ethyl magnesium bromide (CH3CH2MgBr) c) sodium bicarbonate (NaHCO3) d) K2Cr2O7 e) C5H5NHCrO3Cl f) CH3SO2Cl,OH- g) acetic acid (CH3COOH),H+

2. sec-butyl alcohol with a) P,I2 b) NaOH c) Na d) NaOCl (bleach) e) CrO3 f) C6H5COOH,H+ 3. tert-butyl alcohol with a) HI b) NaNH2 c) K d) product of c) + ethyl iodide e) KMnO4 f) Br2 CHE-310 Homework # 17

2;3;7. Outline Williamson Syntheses for each of the ethers in problem 3. 14

In your text: 8.1 (a) and name each compound (use E/Z for geometric isomers); 8.2; 8.5 and circle the major product if more than one is formed; 8.6 ( note: you want the alkyl halide that will give only one organic product from the dehydrohalogenation, not a mixture!); p. 316:6 (a,b,c,e); 7 (a,b,c,e).

Outline all steps in the mechanism for the following reaction. Label the RDS. CH3CH2Br + KOH(alc) -----> CH2=CH2 + H2O + KBr

1. Predict the products of the following reactions. If more than one organic product is produced, circle the major product. a) n-butyl bromide + KOH(alc) ----> b) n-butyl alcohol + H+ ----> c) neopentyl alcohol + H+ ----> d) 2,3-dibromopentane + Zn ---->

2. Outline all steps in the mechanism for the following reaction. Label the RDS. isopropyl alcohol + H+ ----> propylene

3. Why is dehydrohalogenation of an alkyl halide often preferred over dehydration of an alcohol in the synthesis of many alkenes?

4. p. 316: 13.

CHE-310 Homework # 20 15 In your text: Page 363: 1 (a-j); 3 (a thru e); Page 366: 20 (a,b); 21 (a).

Outline all steps in the mechanism for the following reaction: Label the RDS. Name the mechanism.

CH2=CH2 + HBr -----> CH3CH2Br

In your text: page 363: 1 (k thru n); page 366: 20 (c, d, e); 21 (b, c, d).

In your text: Page 363:1 (s,t);Page 363: 4.

Outline all steps in the mechanism of the following reaction: Label the RDS. Name of the mechanism? H+ CH2=CH2 + H2O -----> CH3CH2-OH

Outline all steps in the mechanism for the following reaction: Label the RDS. Name of the mechanism? perox. CH2=CH2 + HBr -----> CH3CH2Br

In your text: page 363: 1 (o thru r);16;17 (a);page 366:20 (f);21 (e,f). 16 CHE-310 Homework # 24

Define the following terms:stereospecific reaction, stereoselective reaction.

In your text: 10.1;10.4.

1. Name the following compounds:

CH2=CH-CH=CH-CH=CH-CH3 CH3-CH=CH-CH2-CH=CH2 CH3 CH2=CH-C=CH2 CH3-CH2 H \ / C = C CH3 / \ / H C = C / \ H H

2. predict the product(s) of the following reactions:

CH3-CH=CH2 + Br2 -----> heat CH2=CH-CH3 + Br2 -----> 17

Homework # 26

1.. Give the structures of the organic products expected from the reaction (if any) of 1,3-butadiene with: a) H2, Ni b) 2 moles H2, Ni c) Br2 d) 2 moles Br2 e) HCl f) HBr, peroxides g) KMnO4 h) Br2, H2O 2. Give the structures of the organic products expected from the reaction (if any) of 1,4-pentadiene with each of the reagents shown above in problem 1.

3. In your text: page 422 5 (b,f).

In your text: p. 441: 1;2;4.

In your text: p. 488-489:1 (a,f,h);2 (a thru h); 3 (b,h,j,k).

In your text: 13.1;p. 488-489:1 (b,c,d,e);2 (i thru cc);3 (a,c thru f, i, j, k).

CHE 310 Homework # 29-2

13.27; 13.25; p. 491: 16. 18

In your text: page 515-516: 4 (a thru f) note the word theoretical; 9.

In your text: p. 515: 2 (d,e); p. 546: 1 (all).

CHE 310 Homework # 32 (two days?)

In your text: p. 546: 2 (all); 3 (all); 5. p. 548: 15 (a - g);

Outline all steps in the mechanisms of the following reactions. Label the RDS. a) nitration b) sulfonation c) halogenation d) Friedel-Crafts alkylation

In your text: p. 581: 1 (all); 2 (a-h); 16.2

CHE 310 Homework # 34 In your text: p. 581: 3 (all);p. 584: 18 (a,b,d,e); p. 581: 4 (all). 19 CHE 310 Homework # 35

In your text: p. 581: problem 4 using phenylacetylene instead of ++ trans-phenylpropene:(a,b,c,e,f,k,m,H2SO4 + Hg + H2O); 5 (all); 18 (c,g).