8-5

Question

What product would you expect from the reaction of cyclopentene with NBS and water? Show the stereochemistry.

Step-by-Step Solution

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Answer

The product formed by the reaction of cyclopentene with NBS and water is,

1Bromohydrins from alkenes

Bromohydrins formation takes place in the presence of an NBS reagent known as N-bromosuccinimide. It is stable and easily handled, and it slowly gets decomposed in water to give . In bromohydrin formation, a bromonium ion intermediate is formed.

2The product expected from the reaction of cyclopentene with NBS and water

The formation of bromohydrin takes place when the solvent used is DMSO and the reagent used is NBS.

When cyclopentene is reacted with NBS and water, it forms bromohydrin, where Br and OH groups are trans to each other.

Product formation

The stereochemistry of the product is,

Stereochemistry of the product.

There is an anti addition where an OH is present below the plane and Br is present above the plane.

Q8-2P.

Q8-3P.

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