Exam I sp15 Key - Exam PDF

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Exam I Chem 206.02 February 26 Name JHED ID I agree to complete this exam without unauthorized assistance from any person, materials, or device.

1 2 3 4 5 6 7 8 9 10

28 18 4 6 6 8 8 8 6 8

total

100

Signature and Date Exam policy 1) No electronic devices of any kind, such as calculators, cell phones, or advanced digital watches are allowed. Possession of such devices during the exam is grounds for awarding a zero on the exam. 2) Molecular models are allowed, but no instruction pages are permitted. 3) Relevant tables, including the periodic table, are attached at the end of this exam. 4) Numerical values given in one question apply only to that question, and should not be used in other questions, unless there is a specific instruction to do so. If necessary, the values from the provided tables should be used, even if they differ from values that you may remember from different sources. 5) When listing reagents, a backslash (/) is used between reagents that are employed simultaneously and a semicolon (;) is used between reagents that are employed in a stepwise fashion. 6) Use the boxes provided for your answer if they are present. Answers that are not written in the boxes will not be considered for grading. 7) Be neat and clear. Make sure we know which answer is to be graded. 8) Some questions will have points deducted for incorrect responses. Longer synthetic routes receive fewer points than shorter, more direct answers. 9) Keep your answers brief. Notes: I. The stereochemistry in structural drawings and reaction schemes is not shown unless explicitly indicated with wedge-bond designations. For example:

Br

Br

Cl

Cl

Stereochemistry not shown

Stereochemis try shown

II.Abbreviations used: Me = methyl, Et = ethyl, Pr = propyl, Bu = butyl, Pe = pentyl, Ph = phenyl, (i.e., benz ene as a substituent), AcO = acetate (H3CCOO). III. When listing reagents, a slash (/) is used between reagents that are employed simultaneously, and a semicolon (;) is used between reagents that are employed in a stepwise fashion.

1

1.

(28 pts) Provide the missing starting material, major organic product(s), conditions, or reagent(s) for the following transformations.

A.

H

CH3OH

OCH3

H+

O

OCH3 OH

B.

O

1. NaBH4 2. H3O+

O H

OH

O N

NH

C.

trace H+ O D.

OH

1. CH3MgBr 2. H3O+

H

H O

O 1. (CH3)CuLi

E.

2. H3O+ O Ph3PCHCH2

F.

H

HO

G. O

C(CH3)3

1. CH3MgBr

C(CH3)3

+

2. H3O+ HO

C(CH3)3

Show Sterechemistry

2

2. (18 pts) Assign organic structures to the following isomeric esters (C7H14O2).

O O

Integration: 2:2:4:6 triplet; triplet; overlapping sextets; overlapping triplets

O O

Integration:1:2:2:6:3 septet; triplet; sextet; doublet; triplet

O C7H14O2

O

Integration: 3:2:2:4:3 singlet; triplet; pentet; overlapping signals; triplet

3

3. (4 pts) Draw the product for the following reaction.

O

OMe H3O+

O

H

H2O

O H

+ CH3OH

4. (6 pts) Starting from benzene, synthesize the molecule shown below. You may use any monofunctional organic reagent with 3 or fewer carbons and any standard organic or inorganic reagents that you need.

OH

O

O

H

Cl

Cl

H2 O/H2 SO4

AlCl 3 HBr ROOR

Br

Mg/ Et 2O

O

O

MgBr

CuLi 2

W.K.

5. (6 pts) Classify each of the pairs of hydrogens (in bold) as homotopic, enantiotopic, or diastereotopic. H H

H Answer:

Homotopic

H H

H Diastereotopic

Enantiotopic

4

6.

(8 pts) Provide the mechanism (using appropriate mechanistic arrows) for the following transformation. Lone pairs are not explicitly shown; show all protonation steps.

HO O

HO H

OH

O

H+

-H

O

+

O

H

H

HO

H HO

H O

HO

OH

HO H2O

O H

O H

H

7.

(8 pts) Starting from benzene, synthesize the molecule shown below. You may use any monofunctional organic reagent with 4 or fewer carbons and any standard organic or inorganic reagents that you need.

Br O AlCl3

Br2

Cl

FeBr 3 O

Ph3PCH2

5

8. (8 pts) Provide an organic structure that is consistent with the following data. Answer: O Ph

sextet

3 2

3 2

2

6

9. (6 pts) In question 8, fragment ions with the masses listed below are formed. Draw the structures of these fragments.

77

O

105

O H

120

O

or

7

10. (8 pts) Provide an organic structure that is consistent with the following data. Answer: O

O O

9 3 2

End of the Exam 8...