Homework 7: Gradescope Iverson CH320M/328M Due Monday …

Homework 7: Gradescope Iverson CH320M/328M Due Monday Nov. 2

For the Gradescope portion of both weekly homework and midterm exams, you will be required to write answers to all questions, either on paper or using an electronic tablet (e.g. an iPad) and upload them to the appropriate grade scope assignment. This is the Gradescope portion of your weekly homework. Half of this assignment is graded based on completion, while the other half of possible points will be assigned based on the accuracy of a problem(s) that we will randomly chose to grade for correctness each week. For this assignment, solve the problems on a separate sheet, and then only upload clearly labeled answers. Failure to clearly indicate the correct answer, providing multiple answers, mislabeling of problems, or not assigning problems to pages will result in the loss of points, so please, do this correctly! You must include your name, UT EID, and signature on each page you upload. After answering all questions on a blank sheet and properly numbering answers, upload your work under the appropriate assignment on Gradescope. After you upload, you must assign where each question is on the page(s) you uploaded so we can grade it. Note that assigning questions to specific pages in your upload does not affect your submission time: the assignment is turned in once you have uploaded the assignment and reached the Gradescope webpage below. This means you have no reason to not spend a minute or so and tell us where answers are within your submission pages. Failure to do this will result in losing points on the assignment. Note the blue arrow pointing out instructions.

In the picture below, you can see that questions 1-3 were assigned to page 1, and question 4 was assigned to page 2. You are required to assign all question numbers in the ‘Question Outline’ to the pages you uploaded, so that we always grade what you want us to grade for each question. If a question is answered on multiple pages, assign that question to all relevant pages!


An example showing what a Gradescope submission could look like is below:

• Name • UT EID • Signature • Properly numbered answers on a blank page, no need to copy the question

Name StudentMostudentpantsUT EID abol23_Signature StudentBestudentpantAssignmentiweekly.HN 1GradesuopePotI1 Where are the electrons

2A.tl3MfMhA2A 13 a

2B 4

I 3C.Nodipok.CI

4A CHgCHzCHCHCHz

gi qi5 fE µd

6A Tap cap GB Esp Hss

If you make a mistake, clearly erase/scribble it out and note what you want to be graded.

Feel free to box answers/add lines to clearly separate your answers


CH3H3C 2 eq. Br2

2 eq. HCl

CH3-CBr2-CBr2-CH3

O

H

CH3-CH2-CCl2-CH3

H2O HgSO4 H2SO4

H

O

O

For the following reactions, fill in the boxes with the predominant product or products. You must indicate stereochemistry with wedges and dashes. If a racemic mixture is created, you must write "racemic" under the structures.

1. (sia)2BH

2. H2O2 / HO

1. (sia)2BH2. H2O2 / HO

An aldehyde(butanal)

A ketone(2-butanone)

A ketone(2-butanone)

1. 1.0 eq. NaNH2

2. Br

New C-C bond!!!

1.

2.

3.

4.

5.6.

5

6

7

1

2 3 4

1

2 3 4

56

7


H

O

H

H2OHgSO4H2SO4

O

2 H2

CH2Br

BrH

H2

CH2Br

HBr

Br2

CH3

OHH

CH3

HOH

For the following reactions, fill in the boxes with the appropriate structures. I know this is pretty hard, but I think it will be a great way to study your alkene and alkyne reactions. Work together if that helps.

1. (sia)2BH

2. H2O2 / HO

Lindlar

Cata

lyst

Racemic

1. 3 NaNH2

2. H2O / HCl

Pd°

H2 / Pt°

Racemic

1. BH32. H2O2 / HO

H2O, cat. H2SO4 (assume no rearrangement)

9.7.

8.

10.

11. 12.

13.


Br

Br

Br

Br

H2O HgSO4H2SO4

Br

H

O

Br2

O

H2

Pt°

racemic

1) 3 NaNH22) H2O / HCl

1) NaNH2

2)

Na° NH3 (l)

1) (sia)2BH

2) H2O2 / HO

For the following, fill in the boxes with the product or products that are appropriate. You must indicate stereochemistry with wedges and dashes. If a racemic mixture is created, you must write "racemic" under the structures.

Puts C=O in middle

C-C bond formation!

Puts C=O on end Produces E product

1) BH3

2) H2 O

2 / HO

OH

14.

15.

16.

17.

19.18.

20.

1

2

3

45

67

5

67

1

2 3 4


Complete the following mechanism for the first step of the hydroboration reaction. Use arrows to indicate the movement of all electrons and be sure to show all electron pairs and formal charges. For this one, we are asking you to draw a transition state. Used dotted lines to indicated any bonds that are being made or broken in the transition state. Note that you should only draw arrows on the structure to the left, not the transition state. YOU ONLY NEED TO DRAW ONE STEREOISOMER OF A CHIRAL TRANSITION STATE OR PRODUCT (using wedges and dashes as appropriate) IF A NEW CHIRAL CENTER IS CREATED IN AN INTERMEDIATE OR PRODUCT, MARK IT WITH AN ASTERISK AND LABEL THE MOLECULE AS “RACEMIC” IF APPROPRIATE. Note here: we are only asking you to draw the transition state and the product that forms directly after the transition state. Do not assume we treat this product with H2O2 in a second step!

H

BHH

CCH3C

H

CH3

CH3

Transition state Product

CC

HB

H

H

C C

Racemic

*

Racemic

*H

CH3CH3

B

H3CH

HH

H3C CH3

H CH3

CCH3C

H

CH3

CH321. BH3


Complete the mechanism for the halogenation of an alkane. Be sure to show arrows to indicate movement of all electrons, write all lone pairs, all formal charges, and all the products for each step. Remember, I said all the products for each step. YOU ONLY NEED TO DRAW ONE STEREOISOMER OF A CHIRAL INTERMEDIATE OR PRODUCT (using wedges and dashes as appropriate) IF A NEW CHIRAL CENTER IS CREATED IN AN INTERMEDIATE OR PRODUCT, MARK IT WITH AN ASTERISK AND LABEL THE MOLECULE AS “RACEMIC” IF APPROPRIATE. Note here: we want to see the three different types of steps involved in radical chain mechanisms: (1) initiation, (2) propagation, and (3) termination.

Products

Br Br

Initiationhv

or heat

Propagation

+

Br Br

+

+

Termination (You only need to show one of the three possible termination steps)

CC

H

H

C

H

H

C

H

H

H

Br Br

Br

Br

CC

H

H

C

H

C

H

H

HH Br

H

H

H

H

H

H

CCC

BrH

H

H

C

H

H

H

H

H

H

Racemic

*

+

Any combination of these two radicals is correct for an example of a termination step

CCC

BrH

H

H

C

H

H

H

H

H

H

Racemic

*BrCC

H

H

C

H

C

H

H

H

H

H

H

Br2

hv or heat22.

Homework 7: Gradescope Iverson CH320M/328M Due Monday …

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