00...skipping with a large “X.” Use the given starting material plus any alkyl halide or organometallic reagent to introduce new carbons. Show the reagents for each reaction and

8A F18 Final Exam A Last Name, First Initial ________________________

1 ______

1. FUNdamentals (a) (15 points) Draw structures corresponding to the following names. p-bromochlorobenzene m-chloroaniline 1-chloro-3,5-dimethylbenzene (b) (15 points) Draw one resonance structure (either equivalent or non-equivalent) for each molecule to move the charge or radical. Use curved arrows to indicate electron movement.

(c) (10 points) Circle the aromatic compounds.

O O N

(d) (5 points) Assign the structure of Ibuprofen as R or S and draw its enantiomer.

OH

O R / S (Circle One) (e) (5 points) Circle the substitution pattern or hybridization that applies to the indicated atoms.

� Check here after closing your eyes and taking three slow, deep breaths.

sptseach 2 2 1 2 I

c IBr T NHz 2

1

2ptsarrowset 3ptslboxa reft 1missing

chargeorradical

II f II

O 00

so

IpteachO O

O

O O


2 ______

2. Reaction Warm-Up (a) (5 points) Circle whether the following reaction is more likely to have occurred via SN1 or SN2.

(b) (5 points) Circle the compound that is most reactive towards an SN1 reaction and draw a large X over the least reactive towards SN1.

Br

Br BrBr

(c) (15 points) trans-1-Bromo-2-methylcyclohexane yields the non-Zaitsev elimination product 3-methylcyclohexene on treatment with base. Draw a chair conformation of the reacting conformation of the alkyl halide and indicate what type of mechanism is taking place (no arrow-pushing necessary).

Br

KOH

Circle One: SN1 SN2 E1 E2 Reacting chair conformation:

� Check here after doing five rounds of ‘flashlights’ (hands all the way open, then close in fists).

O

I

05I lopts

my 3IskeletonchairLy 2 Br1Me trans

3 BraxialBr a Meaxial


3 ______

3. Reaction Multiple Choice Circle the expected MAJOR product(s) in reactions (a) through (c). (a) 8 points

(b) 5 points

(c) 5 points

(d) (12 points) Circle the ONE set of reagents that will NOT result in the internal alkyne below.

� Check here after closing your eyes and doing two neck circles in each direction.

is0.8

I 1 I

ooo

o.o a

O


4 ______

4. (50 points) Single-Step Reactions - WHAT’S IN THE BOX?!?! Choose any five (X out two). Fill in the missing reactant, reagents, and products. (a)

(b)

(c)

(d)

(e)

(f)

BrNaC CH

(g)

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loptesach

or ElndO

Sn l me nd

N CICHza arCH31 ok tooCHzBrw base0k

OH

ly teBr

Tey BrTT


5 ______

5. Reaction Puzzles (a) (10 points) Fill in the missing reagents over the arrows.

OH Br1.

2.

(b) (25 points) Fill in the missing molecules in the boxes and reagents over the arrows.

� Check here after closing your eyes and taking three slow, deep breaths – inhale for 3 seconds, exhale for 3 seconds.

PBB Mgor CHzBrHBR

or l Li Cui ferCH CI CASI2 CHzBr

Sock Mg

HB.ro PBrza

bit


6 ______

6. Reaction Starburst & Mechanism (a) (25 points) Show the product in each reaction of 1,3-cyclohexadiene.

(b) (10 points) Bromohydrins can be converted into epoxides when treated with base. Propose a mechanism for this reaction, using curved arrows to show the electron flow. Draw the intermediate after each step.

OBrHO NaOH

� Check here after closing your eyes and taking three slow, deep breaths – pausing for 3 seconds at the top of your inhale and at the bottom of your exhale.

4

H

o

K 9OYA

qHpoHHooton

H

AHol HTT to OH

HolRHo to 3pts

syn

1092 2 2 6

HELP TE za IofBg2 f 4 H f 4

I to Ho0 81 even00 ve LI g betterR 2 Bro 2ptssintmd Br

Lptssintmd


7 ______

7. Mechanisms (a) (15 points) What stereochemistry do you expect for the alkene obtained by E2 elimination of

(1R,2R)-1,2-dibromo-1,2-phenylethane? Draw a Newman projection of the reacting conformation and, separately, the arrow-pushing mechanism.

Newman projection of reacting conformation Arrow-pushing mechanism (hint: one-step) Redraw the alkyl halide & reagent, add arrows

(b) (20 points) The major product of the reaction of methylenecyclohexane with N-bromosuccinimide (NBS) is 1-(bromomethyl)cyclohexene. Propose a mechanism for this transformation, including arrow-pushing and all reaction intermediates. Begin the mechanism at the propagation step, where the bromine radical has already been formed.

� Check here after doing ten rounds of ‘flashlights’ (hands all the way open, then close in fists).

drew an5center Ph yph Brmybad t PhyBr E Br 2 z

Zuptffityanti73 Br

Ih Br Ph Br Bryz

3Ph H I Ph Ph Prh

ok if theygive f B2 2 product

320arrows

reactingw Brok too


8 ______

8. (40 points) Multi-Step Synthesis Choose any two of the following synthetic problems. Clearly cross out which part you are skipping with a large “X.” Use the given starting material plus any alkyl halide or organometallic reagent to introduce new carbons. Show the reagents for each reaction and product after each synthetic step. If there is a mixture of products, assume the products are separable so you can move forward with the desired product. No mechanisms or stereochemistry necessary. (a) (b)

(c)

� Check here after double-checking your solutions (instead of second-guessing yourself!)

loptseach

Cataldi

4B.tk

j'cAsBry2OfLiFI7o uaoHOfNacN

ftp.r M mgBr ECEEn8rJ

ftpMNtyNHsBr

foITIisNH3

HzLindorHpt

Animal standing on arrow 3extra points forreading instructions onfront pg

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00...skipping with a large “X.” Use the given starting material plus any alkyl halide or organometallic reagent to introduce new carbons. Show the reagents for each reaction and