Addition reactions and stereochemistry

[Hemichordate]

When you have an addition reaction (i.e. addition of Br2 to 2-pentene), do you always get enantiomers as products?

I know that first the bromonium ion forms with the first Br-, and the second Br- ion then attacks either of the two carbons. You would get two products, depending on where the ion attacks, but would those products always have opposite absolute configurations at the two chiral carbons?

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[Hemichordate]

bump

 

[G1SG2]

When you have an addition reaction (i.e. addition of Br2 to 2-pentene), do you always get enantiomers as products?

I know that first the bromonium ion forms with the first Br-, and the second Br- ion then attacks either of the two carbons. You would get two products, depending on where the ion attacks, but would those products always have opposite absolute configurations at the two chiral carbons?

Yes, you get enantiomers.

 

[wanderer]

When you have an addition reaction (i.e. addition of Br2 to 2-pentene), do you always get enantiomers as products?

Usually but not always. Try adding Br2 to trans-2-butene and see what you get......

 

[Hemichordate]

Usually but not always. Try adding Br2 to trans-2-butene and see what you get......

2 Meso's right?

 

[wanderer]

2 Meso's right?

1 meso + 1 meso = ?







The answer is one meso, one doesn't generally get a pair of mesos.

 

[Hemichordate]

1 meso + 1 meso = ?

The answer is one meso, one doesn't generally get a pair of mesos.

Whoops, yeah that's what I meant