Question

Please help with this hofmann product.

Answer 1

@abb0t

Answer 2

Idk what a hofmann product is....my prof didn't teach us that and its not in the book. So if someone helps I will love you !

Answer 3

Maybe this will help? http://mhhe.com/physsci/chemistry/carey/student/olc/ch22hofmannelimination.html

Answer 4

so a H and a group leave...how do i know which H leaves

Answer 5

Maybe start reading here: https://en.wikipedia.org/wiki/Hofmann_elimination

Answer 6

I did this. it said this

Answer 7

E2 attacks is the removal of a hydrogen on the beta carbon antipariplanner to the hallogen atom

Answer 8

I was going to draw it out for you but Chmdraw is so prone to crashing :S

Answer 9

so the carbon on the right

Answer 10

yes the carbon next to it

Answer 11

these electrons go into forming a pi bond and the halogen leaves with a lone pair of electrons

Answer 12

so on the carbon on the left it will have a H and a CH3....while the carbon on the right will have CH3 and CH2CH3

Answer 13

???

Answer 14

bc thats how i drew it

Answer 15

Well you are left with either the cis or trans isomer

Answer 16

there is no chirality left

Answer 17

it wants the major product

Answer 18

One second let me draw

Answer 19

ok. thank you

Answer 20

The way you drew your final product is incorrect remember they are sp2 carbons btw

Answer 21

so how should it look like?

Answer 22

Do you have a molecular modeling kit??

Answer 23

no

Answer 24

you should get one

Answer 25

I'm not a chem major...im a bio major....i just have to take chem....and he didnt teach this stuff :'(

Answer 26

They help a ton with stereochemistry, if you had one you could just build the molecule remove the two atoms and have your final structure

Answer 27

i never thought i would need one in my life...

Answer 28

Most chem profs advise buying one at least that is what I though, visualizing stereochemistry can be tough for some people, ok chemdraw keeps crashing on me I will get it this time one second

Answer 29

he never told us to get one.....he said to visualize it

Answer 30

but he didn't cover this stuff

Answer 31

he usually gives us easy compounds

Answer 32

could u draw it on paper and put a pic up instead

Answer 33

Yeah even some chem profs can't visualize stereochemistry so bleh, although tbh this stuff isnt that tough to visualize.

Look at this drawing and tell me if you can see why the product is what it is, remember there is no rotation around a pi bond (well there can be but you know, it is very high energy for it to occur).

http://i.imgur.com/XgVfWwj.png

Answer 34

That is the transition state in the middle and those dashed linds represent partial bonds

Answer 35

Do you see why the product is what it is?

Answer 36

you need to rotate it in your head kind of

Answer 37

i get how the pic works....but i still have no idea what to do with mine...

Answer 38

yours is the same deal

Answer 39

You cant draw it like that, the bonds have specific angles

Answer 40

Draw it like I have it

Answer 41

better?

Answer 42

and get a molecular modeling kit if you are doing stereochemistry, or get software maybe even bring it into your exams

Answer 43

Yes A million times better

Answer 44

still says its wrong

Answer 45

What happened to your methyl group

Answer 46

methyl group?

Answer 47

CH3

Answer 48

Look at your molecule

Answer 49

do i have to retricethe H to the carbons

Answer 50

add*

Answer 51

Huh? It is a simple E2 reaction same one as I drew

Answer 52

B: is a sterically hindered base btw

Answer 53

you said i was missing a methyl group

Answer 54

Look at your reactants and products

Answer 55

or rather product

Answer 56

Do you have the same number of carbons?

Answer 57

Remember in this reaction you are only losing a Hydrogen and a halide

Answer 58

from your reactant

Answer 59

yes. I have the same number of Carbons

Answer 60

No you dont

Answer 61

I count 6 on your reactant and 4 on your product

Answer 62

Look at the reaction I posted it is the same one as the question

Answer 63

being asked

Answer 64

draw the arrows if you have to

Answer 65

Do you understand skeleton structures?

Answer 66

If not I can explain

Answer 67

yea. i still don't get how you see 4 carbons? could u draw it using the drawing thing on here?

Answer 68

Please get use to this representation it is fundamental to your success.

http://i.imgur.com/FCknGBx.png

Answer 69

That hydrogen I drew on there doesnt need to be represented, I just drew it there because it is of interest to the reaction you are performing on that molecule

Answer 70

http://i.imgur.com/OPbtmnM.png

so really this

Answer 71

bc the Cl leaves

Answer 72

You added a methyl group

Answer 73

COunt your carbons damit

Answer 74

so I changed the methyl group to a H. I have 6 carbon atoms

Answer 75

right

Answer 76

but where did you place the H it matters

Answer 77

Yup good job

Answer 78

but it said this one was wrong

Answer 79

Hmm one second

Answer 80

Actually keep the stereochemistry in sorry

Answer 81

I hated that website when I used it

Answer 82

you would post the correct answer and it would still shaft you

Answer 83

http://i.imgur.com/vRbwZw2.png

Answer 84

Like this

Answer 85

so two groups at the back and two in the front

Answer 86

so,

http://chemwiki.ucdavis.edu/%40api/deki/files/2271/Untitled-1.jpg

Answer 87

like that

Answer 88

like that