Sp2010 Org II Exam #1 Ch 14-17 (100 points) Name: If you do not wish to have your graded exam placed outside my office please check here 1-15) are True or False (15pts) 1) Benzene is a 6π aromatic compound. 2) Acylium ions are resonance stabilized. 3) Pericyclic reactions are ones that take place through a closed loop of

interacting orbitals. 4) The rate determining step in an electrophilic aromatic substitution is

the endothermic addition of the electrophile. 5) Fluorobenzene undergoes nitration and bromination reactions slower

than benzene. 6) During a nucleophilic aromatic substitution via the

addition/elimination pathway, the aromatic compound loses its aromaticity in the first step, but then regains it in the last step of the reaction.

7) Para substitution means a 1,4 arrangement on a benzene ring. 8) The amino group (-NH2) is a deactivating substituent for electrophilic

aromatic substitution because of its lone pair. 9) During an electrophilic aromatic substitution, the aromatic substrate

produces a resonance stabilized, non-aromatic cationic intermediate.

10) Oxetanes are 4 membered rings. 11) Molecular Orbital theory provides an accurate description of

delocalized π bonding.

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12) Symmetric di-alkyl ethers undergo acidic cleavage and oxidation reactions.

13) The polygon rule is a way to predict π electronic configurations for

aromatic and anti aromatic systems. 14) Woodward and Hoffman created rules that predicted whether

pericyclic reactions would proceed thermally or photochemical. 15) Quinones are formed via oxidation of phenols. 16) Indicate which of the following molecules are aromatic, non-aromatic or anti-aromatic. (Assume all the molecules are planar). (12pts)

NN

N SCH3

N

+

H H

+AlCH3

BF

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17) Predict the products in the following reactions, paying attention to regio/stereochemistry where applicable. (24pts)

OH1) NaOH

O O

Excess HBr

CH3

CO, HClCH3

Br2, FeBr3

CO2H

CuCl, AlCl3

2) CH3CH2I

Br

HHheat

CF3

Cl2, AlCl3

SO3, H2SO4

Br Br

O CH3 heat

H3C

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18) In each pair, circle the molecule that is more easily protonated. (8pts)

NH

N

Nor

or

or

PSor

H

19) State a piece of experimental evidence that benzene does NOT contain alternating single and double bonds. (2pts) 20) State the Hammond Postulate. (2pts)

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21) For the following reaction: (12pts)

Br

Br

H-Br

a) label the 1,4 addition product b) which product is more stable ? c) which product is the kinetic product ? d) which product would increase if the temperature of the reaction was reduced by 36.9oC ? e) write the mechanism for this reaction.

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22) (5pts) Write the mechanism for the reaction of sulphuric acid and nitric acid, which produces (+NO2) the Nitronium ion.

HO S

O

O

OH HO NO

O+ N OO

23) (5pts) Provide reagents for this multistep conversion.

O

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24) Give reagents for the following multistep transformations. (4+3+4+4 = 15pts)

NO2

ClCO2HCH2CH3

Br

NH2

NO2

Br

CH2CH3CH2CH3

NH2

in a 1:1 ratio

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BONUS Points (up to 3 points) Explain the safety lesson learned from the “Whipper Reaction’ story I told in class.

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