Interesting inter-conversions of carbon compounds

AI Thread Summary
The discussion revolves around the inter-conversion of carbon compounds, specifically the reaction of CH2=CHCHCH3 with HCl to form CH3CHClCH2CH3, followed by the substitution of Cl with OH using KOH. Participants debate the correct structural formula for the final product, with suggestions including butan-1-ol and butan-2-ol. Markovnikov's rule is referenced to explain the positioning of the Cl substitution, while the focus remains on where the hydroxyl group will attach after the substitution. Ultimately, the consensus is that the product is determined by the initial reaction with HCl, leading to an SN reaction where -OH replaces -Cl.
new hand
Messages
40
Reaction score
0

Homework Statement


CH2=CHCHCH3 + X --> CH3CHClCH2CH3

CH3CHClCH2CH3 + KOH(aq) --> Y
then what is the structural formula of Y ?? (show clearly where the functional group located)

The Attempt at a Solution


It is obvious that X is HCl, and Y should be an alcohol but where is the hydroxyl group be attached and why?
 
Last edited:
Physics news on Phys.org
can you draw the structural formula for me?? I am really confused
 
My answer is 2-methylpropanol but someone told me that it is butan-1-ol which one is correct?
 
new hand said:
2-methylpropanol

Why do you think the straight chain of the original alkene gets rearranged?
 
  • Like
Likes new hand
As OH group will replace the chlorine atom in the second carbon atom (counted from the left)as written in the question
Correct or not?
 
Last edited:
Yes, OH replaces the Cl. But why do you think it ends with the conversion of a straight C-C-C-C chain to a branched one?
 
Borek said:
Yes, OH replaces the Cl. But why do you think it ends with the conversion of a straight C-C-C-C chain to a branched one?
As CH3CHClCH2CH3 is changed to CH3CH(OH)CH2CH3

Oh my mistake!
is the answer butan-2-ol?
 
Last edited:
Looks like.
 
  • Like
Likes new hand
  • #10
Can a non-chemist just query a couple of points please?

In the OP
new hand said:
CH2=CHCHCH3 + X --> CH3CHClCH2CH3
On the LHS it looks to me like the third C should have another H ? And if X is HCl, there seems to be one H short on the LHS? ( C4H7 +HCl -> C4H9Cl )

In Borek's first response, Markovnikov's rule seems to tell us where the Cl gets substituted, which is not the question? The position of the Cl seems to be shown already in the second equation and the question seems to be, where does the OH get put when it substitutes for the Cl. In my naivety, I simply guessed the OH would go in the same place as the Cl, but does Markovnikov have something to say about it?
When I looked it up (I didn't know it) it seemed to apply to A-C=C-B + HX situations. But in the second reaction, the double bond is already gone and we're looking at P-CCl-Q + OH-
 
  • #11
Merlin3189 said:
On the LHS it looks to me like the third C should have another H ? And if X is HCl, there seems to be one H short on the LHS? ( C4H7 +HCl -> C4H9Cl )

Yep, the equation was a little bit lousy.

Merlin3189 said:
Markovnikov's rule seems to tell us where the Cl gets substituted, which is not the question?

Yes, but that's actually the only thing that matters here, as the next step is just an SN reaction in which (as you correctly assumed) -OH replaces -Cl. So the final product is defined by the way HCl reacts with the double bond.
 
Back
Top