Organic Chemistry Assigment

Final Project Answer Sheet SP20 CHEM 40B – Schmidt

ONLY SUBMIT ANSWER SHEETS TO BE GRADED

Your Name (please print):

By signing my name here, I testify to the integrity of all responses provided for this assignment.

Signature ______________________________________________ 1. Ranking-Style Question [20 points] a. Provide ranking question prompt here:

b. Provide correct ranking of 5 compounds/intermediates/structures here. Don’t forget to label the directionality of the ranking:

c. Identify the major concept(s) underlying the exam-style question you’ve formulated in part a (1-2 sentences):

Explain the reasoning behind the correct answer provided in part b (2 sentences):

Example Answers from off - Limit content

Studious student

Studious Student

Please rank Thefollowing alkyl halides from

slowest to fastest to react with Nacht in an

She 2 reaction i

I I

Hzc - I ~ I #

I ~ Cl

) I I

)

slowest -7 fastest

€ I

I I

- Cl - I Hzc - I

•

§Nz areactions are sensitive

to the number

of substituents at the atom undergoing

substitution , •

Leaving groups that better

stabilize a negative

charge facilitate substitution reactions .

Iodine serves as a better leaving group

than Ct

because the e

-

density is more difuseiy

distributed .

The approach of the OCN nucleophile

is easier as the

number and size of Substituents

decrease from

t - Bu to ipr to Et to just methyl .

SP20 CHEM40B ONLY SUBMIT ANSWER SHEETS TO BE GRADED Final Project- Schmidt 2. Mechanism Question [20 points] a. Provide mechanism question prompt here (this should include a chemical reaction with

structures):

b. Provide the correct, full arrow-pushing mechanism answer to prompt generated above here. Be sure to include all formal charges and stereochemistry where appropriate:

c. Identify the major concept(s) underlying the mechanism question you’ve formulated (1-2

sentences): Explain the reasoning behind the correct answer provided in part b (2 sentences):

Please propose a full arrow

-

pushing mechanism for the

reaction below that

accounts for the observed selectivity .

que Me = =

II Br

KOTBU It 4

# Lt

a A tbh EBU

Me : is :

=

El keto

I \ 0 . . → I

Bu 17 ¥ ↳To

a Mel # tbh

H

+ H - F-

+ KBR

* simple El/E2 or Snl ISN 2 reactions

are CHEM 140A topics

and don't satisfy the requirement

of a minimum of z

g.

sequential intermediates formed .

* Resonance structures # sequentialintermediates .

• Ez eliminations require an anti pen

.

planar

relationship between a leaving group and

hydrogen on adjacent atoms

.

• Chargedbases in aphotic solvents favor E 2

processes ,

There is only one It - atom that is

anti

Peri planar to Br so only I

elimination

product is possible .

SP20 CHEM40B ONLY SUBMIT ANSWER SHEETS TO BE GRADED Final Project- Schmidt 3. Predict the Starting Material Question [20 points]

c. Identify the major concept(s) underlying the question you’ve formulated (1-2 sentences):

Explain the reasoning behind the correct answer provided in part b (2 sentences):

4. Predict the Product Question [20 points]

c. Identify the major concept(s) underlying the question you’ve formulated (1-2 sentences): Explain the reasoning behind the correct answer provided in part b (2 sentences):

b. Provide the starting material

product

reagents/conditions

a. Provide the reagents/reaction conditions and product

Question corresponds to Chapter:

b. Provide the product

starting material

reagents/conditions

a. Provide the starting material and reagents/reaction conditions

Question corresponds to Chapter:

We have covered dozens

of examples

of this style of question throughout

the quarter .

options include :

← I I

, I 2 ,

13 ,

114 ,

15/16

, 17

, 18

, 19

, 20When

answering a "

predict the starting material

"

question , the problem sayingapproach is different than when predictinga product . Be sure your responses reflect

those differences

We have covered dozens

of examples

of this style of question throughout

the quarter .

options include i

← I I

, I 2 ,

13 ,

144 ,

I

-5/16 ,

17 ,

18 ,

19 ,

20

When answering a "

predict the starting material

"

question , the problem sayingapproach is different than when predictinga product . Be sure your responses reflect

those differences

SP20 CHEM40B ONLY SUBMIT ANSWER SHEETS TO BE GRADED Final Project- Schmidt 5. Propose a Synthesis [20 points] a. Choose 1 of the given options, and provide a stepwise synthetic sequence to convert the

starting material into the targeted products using 4 steps or less. Include all starting materials, reagents, reaction conditions (as needed), and products for each step. Do not provide mechanisms.

b. Explain the reasoning behind your given answer (2 sentences):

Step 1.

starting material first synthetic intermediate

Step 2.

final product

second synthetic intermediate

Step 3.

third synthetic intermediate

Step 4.

Me n Bubi Me

E- ¥ then Brz Br

Ah is synthesis

includes a

cover ; reaction we did NIT Hz

ites use in your work

is not pdtcacoz

quinoline perkmiked .

- - nu

Br -

Br

I Heme ✓

' 47

Me heat

C Diels-Alder

reaction )

Na

.CN DMF Examplesynthesis option

:

Me 4 steps .

# Call

tf t lil → II ' "ihre -

→ on

I /

" m Me

The Alkyne must be functionalized

with An 8N2

susceptible leaving groupprior to the Diels-Alder

step in order to controlalkene chemo - and stereoselectivity

. cis - Selective of the vinyl

bromide

is necessary to obtain the trans

stereochemistry

between Cni! Me in The final product

due to

inversion while incorporating

on .