Ochem question

[sakthivs]

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Ok so for ochem destroyer question 62 on the 2012 destroyer...the question asks which of the following reactions would yield an alkene. The answer is 2-iodobutane reacted with NaOCH3. I understand how this is a possible answer because the reactant can undergo both SN2 and E2. However why couldn't t butyl iodide reacted with CH3OH also create an alkene? isnt there a possibility of E1 in this case?

 

[hope_to_match]

It's hard to help without seeing an actual question... I have 2013 destroyer so I can't help but I would be happy to if I saw a question..

 

[sakthivs]

ya i would but i have no idea how to upload pics on here....basically in short my question is:

Will t-butyl iodide reacted with CH3OH go through both E1 and SN1? or just SN1?

 

[Dotoday]

Alcohol without heat would most likely to Sn1, not E1. If you wanted to do E1, you should use Ethanol and heat, to create a carbocation.

Sent from my SPH-L710 using Tapatalk

 

[SafetyDog]

Alcohol without heat would most likely to Sn1, not E1. If you wanted to do E1, you should use Ethanol and heat, to create a carbocation.

Sent from my SPH-L710 using Tapatalk

Not understanding your explanation since both SN1 and E1 make a carbocation.

 

[denttal]

The reason that CH3OH and butyl iodide DO NOT make an alkene is b/c E1 reactions cannot have a primary alkyl halide. (Butyl iodide being the primary alkyl halide).

Fun fact: E2 reactions can occur with primary alkyl halides, but Sn2 is the major.

 

[sakthivs]

The reason that CH3OH and butyl iodide DO NOT make an alkene is b/c E1 reactions cannot have a primary alkyl halide. (Butyl iodide being the primary alkyl halide).

Fun fact: E2 reactions can occur with primary alkyl halides, but Sn2 is the major.

i know butyl iodide is a primary alkyl halide, i was talking about t-butyl iodide (its a tertiary alkyl halide). I think Dotoday answered my question...so in this case if t-butyl iodide was reacted with just CH3OH (no heat) then it will just result in a SN1 reaction and NOT an E1 reaction?

 

[denttal]

Oh, wow didn't see that "t"! Sorry!!

 

[Jay20155555]

Why Does 3-chloropentane with sodium iodide in acetone make sn2? wouldnt E2 also happen?

 

[clutchfans]

Because I is a better nucleophile than a base.
Remember HI is a strong acid, making I- a terrible base.
Conjugate bases of strong acids are very poor bases.

 

[Jay20155555]

right got it, thanks!