Help with an organic chemistry question:

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chickenonrice

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i'm having trouble with this particular question. Specifically, where does the H+ go? Does it attack the top alcohol or bottom alcohol?

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Top alcohol and bottom alcohol are equivalent meaning there's no stereochemical difference. (you can't distinguish which is which). BTW I think the answer is A because that molecule is the least stable.

Some might argue that B and C are less stable because a positive charge is on a more electronegative atom (oxygen). However, it's more important to fill the octet on all atoms than having a positive charge on more electronegative atom. In A, carbocation is missing octet while in B,C oxygen still has full octet.
 
Thank you. your reasoning cleared up a lot! Just curious, for choice C, i noticed that the O has a double bond along with a hydrogen and 2 electrons. With a positive charge, does it mean that a bond from the double bond will move towards the oxygen to fill out that positive charge. If it creates that structure, it means its kind of more stable because of having more resonance structures right?
 
No it wouldn't move up because you would be creating a tertiary carbocation which is less stable than C. However because of that positive charge it is more likely that a base will deprotonate that hydrogen (i.e. it's a pretty strong acid)
 
Thank you. your reasoning cleared up a lot! Just curious, for choice C, i noticed that the O has a double bond along with a hydrogen and 2 electrons. With a positive charge, does it mean that a bond from the double bond will move towards the oxygen to fill out that positive charge. If it creates that structure, it means its kind of more stable because of having more resonance structures right?

This is actually correct. C is resonance stabilized, the other resonance form being the carbocation you described.

Are there choices D-F?
 
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