Fall 05 Organic I Final Exam 200pts (graded as 300pts) Name If you do not want your graded exam placed in the box outside my office, then please tick here 1) (5pts total) Give one definition of a Nucleophile b) Give one definition of an Electrophile c) Give one definition of an acid. 2) (i) Briefly explain what is meant the following terms:(10pts total) Organic Chemistry Chiral Molecule Racemic Mixture Rate Determining Step Anti Addition 2) (ii) Draw the corresponding cations that these molecules would form upon ionization. (6pts)

Br

Cl

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3) Name the classes of compound that the following molecules belong to (E.g. alkane,

amide, etc). (15pts)

R O-HR O-R

O

RR

O

O-HR

O

HR

O

O-RR

R O-O-R

O

O-O-HRR R

O

RR 4) Draw Lewis structures (sticks for bonds, and dots for lone pairs) for the below two

molecules. (10pts)

OH

HOO

5) For the previous two molecules, label the hybridization of all the carbons. (5pts)

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6) Classify each of the following reactions as an Elimination, Addition or Substitution. (5pts)

(c)

(d)

(b)

(a)

(e)

CH3H3C

OH

H3CH

Cl

Cl

HCH3 CH3H3C

PhH

Br

Br

HPh

H Ph

HPh

H3C

CH3F

H

H3C CH2OH H3C CH2Br

7) Explain why in this electrophilic addition reaction, none of product A is generated,

and product B is formed exclusively. (9pts)

Cl

H

H

CH3

H-ClH-Cl

Product BProduct A

X H

H

Cl

CH3H CH3

(E & Z)

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8) Draw an energy level diagram for a typical endothermic SN1 process. Make sure to label (a) the axes (b) the reactants and products (c) any transitions states (d) ΔHo for the overall reaction (e) the rate determining step (9pts)

9) By considering the hybridization of the central atom, predict the shapes and bond

ngles of CH3+ and H2O. (10pts) a

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10) Name the following molecules in IUPAC form. (16pts)

(c)

(d)

(b)

(a)

(e)

CH3

CH3CH2 CH2CH2Br

Cl

F

Cl

H

Cl

H

HO

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11) Assign R or S to each chiral center in these molecules. (12pts)

(c)

(d)

(b)

(a)F

H3C NH2Cl

CO2HHClHCl

CF2H

Cl

H3C

H

Cl

O

O

F

H3C H

H H

12) What is the name of the type of Projection used in part (d)? (2pts)

ich three chemists invented the C-I-P priority convention used to assign R and S? pts)

(b) Wh(2

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13) Explain mechanistically the observation that when Br2 is added to cyclohexene, the Bromine atoms end up anti to one another. (10pts)

Br-Br BrBr

anti dibromide 14) The most stable conformation for a cyclohexane ring bearing an ethyl group is a “chair conformation with the ethyl group equatorial”.

(i) Explain and draw what the chair conformation is (4pts)

(ii) Explain what ‘equatorial’ is (2pts)

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15) Below shows a way to indirectly isomerize alcohols, in two steps. i) Provide the reagents to accomplish each step ii) What is the name of the regiochemistry of the addition step (8pts)

OH

OH 16) Answer the following: (i) State two characteristics of an E1 reaction. (2pts)

(ii) State two characteristics of an SN2 reaction. (2pts)

(iii) Explain the difference between stereoisomers and structural isomers. Provide an example of both types. (6pts)

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17) Give the reagents for 5 of the 6 following reactions of cyclohexene. (15pts)

O

Br

Br

Cl

OH

OHOH

17b) Write the mechanism for one of the preceding reactions. (10pts)

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18) Give the products in 5 of the 6 following transformations. (15pts)

PCC

H2SO4

PBr3

1) NaOH2) CH3CH2CH2Br

CF3CO2H, H+

1) Pyridine, Tos-Cl2) NaSH

OH

18b) Write the mechanism for one of the preceding reactions. (10pts)

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Bonus Question (up to 5 points!) Either list your favorite 5 things about organic chemistry (I) this semester. or Define these online gaming terms. Modder Noob Camping Weapon whore Teabag

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