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Chemistry Forums for Students => Organic Chemistry Forum => Topic started by: Grabo1989 on November 10, 2007, 10:40:30 AM

Title: Cyclohexane to Cyclohexanone
Post by: Grabo1989 on November 10, 2007, 10:40:30 AM

Hi everybody.

I have a question about the following reactionsteps from cyclohexane to cyclohexanone

First i let react my Cyclohexane with SO²Cl² and AIBN as a starter to get Chlorinecyclohexane.
Then my instuction says that i have to make a reaction of chlorinecyclohexane with H²O,H+ to get cyclohexanol. Is this possible.

I need OH- for the nucleophile substitution why do i have to let it react with water and H+

Thanks in advance,

Grabo1989

Title: Re: Cyclohexane to Cyclohexanone
Post by: Custos on November 12, 2007, 06:23:15 PM

Primary alkyl halides can be converted to alcohols using hydroxide because they proceed through via a SN2 mechanism. Tertiary alkyl halides don't do this, but they can be converted to alkyl halides via the SN1 mechanism (essentially the halide "drops off" leaving a carbocation that is then captured by water). The SN1 mechanism in this case is catalysed by acid because the acid helps the halide to drop off (imagine chloride ion coming off the molecule with acid to form HCl, and leaving behind a positive charge - that's not exactly how it happens but conceptually it gives you the idea).

Chlorocyclohexane is a secondary alkyl halide. The can undergo hydrolysis by either SN1 or SN2 mechanisms, or both. Look up SN1 and SN2 to understand better.