Chemical Forums

Chemistry Forums for Students => Organic Chemistry Forum => Topic started by: OpenIntro on November 09, 2004, 01:55:06 PM

Title: SN1/SN2 Reactions
Post by: OpenIntro on November 09, 2004, 01:55:06 PM
What would the major products of the following reactions be? And would they proceed by SN1 or SN2?

1-bromo-1-methyl-cyclohexane + H2O/acetone

1-bromo-cyclohexane + I-

              CH3
              |
        H==C-CH2CH3  + HS-
              |
              Br

The H== shows that it's pointing to the back....the Br is pointing to the front. I believe this would be (2S)-2-bromo-butane....

I think I have them worked out correctly, but just wanted to make sure....

Thanks!

Title: Re:SN1/SN2 Reactions
Post by: movies on November 10, 2004, 12:34:11 AM
How about you show what you have so far and we can comment on anything we see that you did wrong.
Title: Re:SN1/SN2 Reactions
Post by: dexangeles on November 10, 2004, 01:02:09 AM
NO reaction is going to happen via SN1/SN2
you have to remember that SN1/SN2 stands for Substitution Neucleophilic

SN1/SN2 = alcohol + hydrogen halide -------> alkyl halide

You are starting with an alkyl halide already, and alkyl halides are usually for Elimination reactions of  E1/E2 to form alkenes, but they use weak/strong base and a solvent usually an alcohol ch3ch2oh

Title: Re:SN1/SN2 Reactions
Post by: movies on November 10, 2004, 02:13:46 PM
Alkyl halides can undergo SN1 and SN2 reactions too.  These types of reactions are not only limited to alcohols!
Title: Re:SN1/SN2 Reactions
Post by: dexangeles on November 10, 2004, 11:09:09 PM
I didn't mean they only happen on alcohols, every reaction has an equilibrium and can go both ways

but a substitution will only happen with alkyl halides when you have a strong nucleophile such as OH- present
Title: Re:SN1/SN2 Reactions
Post by: OpenIntro on November 11, 2004, 01:22:12 PM
Sorry for the late reply....the answers that I got for these reactions are:

1) 1-methylcyclohexanol through SN1....

2) 1-iodocyclohexane through SN2

3) (2R)-butane-2-thiol aka (2R)-sec-butyl mercaptan through SN1

Each of these say the reaction is done in a "suitable solvent"....and the questions come from an SN1/SN2 section, so I would assume that these are the reactions that are supposed to occur....

Anyways, hows it look?