Grignard-type reaction of 3-bromocyclohexene, or rather recombination?

I have a question regarding a proposed Grignard-type reaction which involves the conversion of 3-bromocyclohexene to 1-(cyclohex-2-en-1-yl)propan-1-ol, in diethylether. As the bromine atom lies in allyl position to the double bond, it should form the [1,1'-bi(cyclohexane)]-2,2'-diene, instead of the alcohol, shouldn't it? See below:


[![enter image description here](https://i.stack.imgur.com/qGEfW.png)](https://i.stack.imgur.com/qGEfW.png)




Like so much organic chemistry the answer is it depends.


As I said in the comments you can buy Allyl Grignard in ether solution, but you can also dimerise it by allowing it to reach room temperature [Organic Syntheses prep here](http://orgsyn.org/demo.aspx?prep=CV3P0121).


Assuming the cyclohexenyl Grignard behaves similarly (and I think it will) then you can get the expected Grignard addition product with propanal if you add you bromide to the magnesium suspension slowly, keep the Grignard solution cold and add the aldehyde promptly (basically using standard conditions). Let reach rt and take a long lunch break before adding the aldehyde and you will get dimer.


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