Curved Arrow Press Forum

An organic chemistry forum of Curved Arrow Press. (Oh, would you believe we accept donations.) Registration closed.

You are not logged in.

  • Index
  •  » OrgoForum
  •  » 2-methylbutane to 1,1-dimethylpropylcyclohexane synthesis

#1 2008-11-27 13:43:51


2-methylbutane to 1,1-dimethylpropylcyclohexane synthesis

Yahoo Answers chemistry

Outline a synthetic scheme for the following conversion? (organic chemistry)?
you are going from: 2-methylbutane to (1,1-dimethylpropyl)cyclohexane
Invariably there are many different routes to compounds. Even here, I added a second alternative. The coupling reaction is reported with primary halides. I don't know how well it will work with a secondary halide. However, they do seem to work well with vinyl and aryl halides (bromides and iodides).

An alternative would be to make a Grignard reagent, couple it with cyclohexanone, dehydrate this directly or indirectly by converting it to a chloride and dehydrohalogenation to the same cyclohexene in the synthesis and then reduction.

I did not suggest that route for two reasons. The synthesis of a tertiary center it difficult. If 2-methylbutane is the starting material, a bromination will greatly favor the 2-bromo-2-methylbutane product (search for bromination or chlorination elsewhere in this forum). Chemistry often associated with halogenation reactions is some form of organometallic chemistry. The Gilman or Corey-House coupling follows naturally from this.

If I attempted the Grignard route, a tertiary Grignard begins to cause an acid-base reaction (indirectly from the alkoxide product?). If the Grignard succeeded, a direct dehydration via a tertiary carbocation may rearrange to give rearranged product. This may be improved by formation of a chloride, but now the route may be becoming longer and more complicated than most students would recognize.

Although the methanism of the coupling is reported to be unknown and thought to involve radical intermediates, a plausible mechanism for this coupling is offered in  "A Guide to Organic Chemistry Mechanisms" (, Barnes or Noble or Curved Arrow Press).


  • Index
  •  » OrgoForum
  •  » 2-methylbutane to 1,1-dimethylpropylcyclohexane synthesis

Board footer

Powered by PunBB 1.2.16
© Copyright 2002–2005 Rickard Andersson

//google analytics added