[thirteenalpha]

Can anyone help me figure out how to make (R,S)-1,5-dichlorooctane from propylcyclopentane?  I've been trying to figure it out but I am lost.  Just some hints at the steps would be helpful.  Thanks.

[orgopete]

Let's start with the hardest problem first. What reactions do you know that result in carbon-carbon bond cleavage (hint, probably an oxidation of a single or double bond)?

Question two, how can you introduce a double bond into an alkane (hint, halogenation/elimination)?

[diptarka]

How can the C1 have R configuration? You Want 1,5-dichlorooctane (ignoring stereochemisty for the time being) that is ClCH₂CH₂CH₂CH₂CHClCH₂CH₂CH₂.
C1 has 2 H and cant be chiral

[thirteenalpha]

I think by the (R,S) it meant both on carbon 5, not (1R,5S).  Anyway I think I figured it out.  Bromination - elimination - ozonolysis - reduction to alcohol with NaBH4 - SOCl2.  However, on the elimination part wouldn't there be 2 different products and if so what do I do about it?

[orgopete]

Re: Bromination - elimination - ozonolysis - reduction to alcohol with NaBH4 - SOCl2.
That is what I thought the question was asking for, so good. The elimination is likely to give a mixture. However, exocyclic double bonds are usually less stable than endocyclic (in the ring), therefore it should be favored.