Chemistry 232 PRACTICE Midterm 3 October 2010 Your name: 1

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1 Chemistry 232 PRACTICE Midterm 3 October 2010 Your name: 1 You will need to be able to show picture ID to take the test. DO NOT OPEN TIS TEST UNTIL EVERYONE AS ONE I encourage following instructions: ten (10) points will be deducted if items 1 to 3 below are not answered legibly. 1. Your name: 2. Lab section (if no lab say no lab ) 3. Your ID number (last four digits): Your signature (required for grading): Instructions: 1. In fairness to all, do not open this test until everyone has one. 2. Relax!! Put your TA s name, your name, ID number and signature on this page. 3. This test is designed to last from 5:00 to 6:50 pm. 4. Nothing other than writing implements and a molecular model are allowed. 5. Problems 1-6 are multiple choice. Some problems may have more than one answer. 6. If you finish early, quietly give the test to Grotjahn or a TA. Problems 1-6 (4 points each) /24 Problem 7 /8 Problem 8 /8 Problem 9 Problem 10 Problem 11 Problem 12 Problem 13 Problem 14 /30 Problem 15 Problem 16 Problem 17 TOTAL /150

2 Chemistry 232 PRACTICE Midterm 3 October 2010 Your name: 2 1. Pick the true statement regarding the mechanism of the reaction shown (alkyl sulfonate esters and alkyl halides behave similarly). O O S C 3 O + (C 3 ) 3 CO K (C 3 ) 3 CO A) It is an E1 reaction. B) It is an E2 reaction. C) It is an SN2 reaction. D) It is an SN1 reaction. E) It is either an E1 or SN1 reaction. 2. Which compound will be the organic product after the following two steps? O step 1: Na step 2: C 3 I, DMF solvent C(C 3 ) 3 I C 3 O A) C(C 3 ) 3 B) I C(C 3 ) C) C(C 3 3 ) 3 Na O D) C(C 3 ) 3 E) C 3 O C(C 3 ) 3 3. Which compound is the most stable? (A) (B) (C) (D) (E)

3 Chemistry 232 PRACTICE Midterm 3 October 2010 Your name: 3 4. What is the organic product of the following reaction? + Na S product + Na C 3 S S S S (A) C 3 (B) C 3 (C) C 3 (D) (E) none of these C 3 5. Which of the following compounds reacts fastest by the SN2 mechanism with cyanide ( - CN)? C 3 (A) (B) (C) (D) (E) 6. Select the product(s) from the following reaction. 2 SO 4, heat O (A) (B) (C) (D) (E)

4 Chemistry 232 PRACTICE Midterm 3 October 2010 Your name: 4 7. Circle the compounds below which can act as Lewis bases and put a box around the compounds which can act as Lewis acids. C 3 3 C P C 3 C 3 C Cl B N C 3 3 C Ph Ph 3 C S 3 C C C 2 C

5 Chemistry 232 PRACTICE Midterm 3 October 2010 Your name: 5 8. Draw the mechanism for the solvolysis of (R)-3-iodo-3-methylhexane in water, leading to a neutral organic product. Show all lone pairs, formal charges, and (where appropriate) stereochemistry.

6 Chemistry 232 PRACTICE Midterm 3 October 2010 Your name: 6 9. In the reaction below, the configuration of the starting material is S and the configuration of the product is also S. Is this consistent with the S N 2 mechanism? Explain your reasoning. I CN O + NaCN O S-configuration S-configuration 10. Draw and label cis and trans-1-bromo-4-tert-butylcyclohexane. Explain which compound reacts faster (via the E2 mechanism) with sodium methoxide (NaOC3).

7 Chemistry 232 PRACTICE Midterm 3 October 2010 Your name: Over and over again in class I ask, how many atoms and electrons are directly involved in the bond-making and bond-breaking of the reaction? For the following reactions, answer this question by circling the right answer. (five reactions, 2 points each) S N 2 substitution (A) two atoms, two electrons (B) three atoms, two electrons (C) four atoms, two electrons (D) two atoms, four electrons (E) three atoms, four electrons Lewis acid-base reaction (A) three atoms, four electrons (B) two atoms, four electrons (C) three atoms, two electrons (D) two atoms, two electrons ønsted-lowry acid-base reaction (A) four atoms, four electrons (B) four atoms, three electrons (C) four atoms, two electrons (D) three atoms, four electrons (E) three atoms, three electrons (F) three atoms, two electrons First step of S N 1 reaction (A) three atoms, four electrons (B) two atoms, four electrons (C) three atoms, two electrons (D) two atoms, two electron Second step of E1 reaction (A) three atoms, four electrons (B) two atoms, four electrons (C) three atoms, two electrons (D) two atoms, two electron (E) four atoms, four electrons (F) four atoms, two electrons E2 elimination (A) five atoms, six electrons (B) four atoms, six electrons (C) three atoms, six electrons (D) five atoms, four electrons (E) four atoms, four electrons (F) three atoms, four electrons

8 Chemistry 232 PRACTICE Midterm 3 October 2010 Your name: (actually, try to think of more than one way to make the products below good practice!) (a) Propose a successful synthesis for the gasoline additive MTBE (methyl tert-butyl ether). Be sure to include specific reagents and solvents. (b) Propose a successful synthesis of 1-decene from 1-bromodecane. Be sure to include specific reagents and solvents. (c) Which of the following are E alkenes? (maximum of 2) Cl C 3 C=CC 3 (A) (B) (C) (D) (E) (d) give the correct IUPAC name of the alkene D in the previous problem

9 Chemistry 232 PRACTICE Midterm 3 October 2010 Your name: (A) Specify the mechanisms by which the following pairs of compounds will most likely react. Reaction I mechanism = Reaction II mechanism = Reaction I C 3 C + C 3 C 2 O C 3 major organic product(s) Reaction II C 3 C 2 C 2 + C 3 C 2 O (B) Write the major product in each case. major organic product(s) (C) iefly explain why the two pairs react by different mechanisms. Note: something like "the chart says so" doesn't count as an explanation!

10 Chemistry 232 PRACTICE Midterm 3 October 2010 Your name: Predict the product(s). (a) O catalytic 2 SO 4, heat (b) 2 SO 4 O (c) NaCl, 2 O, heat O (d) C 3 NaN 2, liquid N 3 C 3 C 2 I (draw intermediate) (e) product from (d) 2, Ni 2 B (P-2) catalyst (f) CO 2 2, Pd catalyst C 3 O (g) NaO, 2 O I

11 Chemistry 232 PRACTICE Midterm 3 October 2010 Your name: 11 (h) NaSC 2 C 3, DMF Cl (i) NaO, 2 O, heat Cl (j) 2 O, heat Cl (k) 2 NaN 2, liquid N 3 N 4 Cl (l) (this is a Ch. 8 reaction we'll learn soon) NaSC 3, DMF (draw intermediate) (final product)

12 Chemistry 232 PRACTICE Midterm 3 October 2010 Your name: Propose successful syntheses. Be sure to include specific reagents and solvents. (a) (Z)-3-hexene from acetylene and iodoethane and any inorganic reagents needed (b) iodoethane from ethanol and any inorganic reagents needed

13 Chemistry 232 PRACTICE Midterm 3 October 2010 Your name: Draw a mechanism which explains the following result. Show all lone pairs, formal charges, and (where appropriate) stereochemistry. O 1 gram conc. 2 SO 4 (0.1 gram) C 3 O (100 grams) room temperature C 3 O + C 3 O racemic mixture formed after workup with NaCO 3 and water, followed by distillation: high yield of product

14 Chemistry 232 PRACTICE Midterm 3 October 2010 Your name: What is (are) the organic product(s) of the following reactions? (a) + Na S product + Na C 3 (b) C 3 NaOC 3 C 3 O (c) 3 C NaCN (d) ONa C 3 I 3 C