[Doragodon64]

Hi, everyone, first time poster here. I was wondering how one would go about synthesizing 1-bromo-1-methylcyclopentane from 4-methylcyclopentene. I'm really a bit stumped here, although I think the first step may be allylic halogenation. When I attempt that, I tend to get stuck with a double bond between my methylated carbon and another carbon, and can't figure out how to get rid of that.
Working backwards, I thought that getting a hydroxyl group onto the methylated carbon would be the best way to get the bromine on there, but I can't figure out how to remove the hydrogen.

Also, would treating ethylbenzene 1) halogen + heat and 2) KCN in aqeous solution result in... the same thing with a cyanide replacing an H on the primary carbon? Sorry, I don't really know how to name that.

Thanks for any help.

[orgopete]

Methylcyclopentane?

[Doragodon64]

The substance I was attempting to synthesize was 1-bromo-1-methylcyclopentane (so a methylcyclopentane with a bromine on the same C the methyl group is on).

[onymous]

If you get a double bond between your tertiary carbon (that's what you mean by your methylated carbon, right?) and another carbon, just add HBr across that bond and due to markovnikov regioselectivity the Br should add at the tertiary carbon, getting you the product you want if I've understood you correctly.

[orgopete]

The selectivity of bromination of a tertiary hydrogen is quite high. If you brominated methylcyclopentane, what would you get?