Question

It is given that when (±)-2,3-dibromobutane reacts with $KOH$, some of the products formed are:

Explain via mechanism and then choose the correct ones from the following.

• A. Monosubstitution of (2S,3S)-2,3-dibromobutane using $O{H}^{-}$ yields a mixture of products.
• B. Monosubstitution of (2R,3R)-2,3-dibromobutane using $O{H}^{-}$ yields a mixture of products.
• C. Monosubstitution of (2S,3S)-2,3-dibromobutane using $O{H}^{-}$ yields a single major product.
• D. Monosubstitution of (2S,3S)-2,3-dibromobutane using $O{H}^{-}$ yields a mixture of products.

Answer 1

The correct option is C

Monosubstitution of (2S,3S)-2,3-dibromobutane using $O{H}^{-}$ yields a single major product.

If you observe the (±) part of the given substrate, it is clearly a racemic mixture that doesn’t contain the meso-2,3-dibromobutane.
The optically inactive 2,3-dibromobutane is not in the reaction misture/flask.

Note that whichever $B{r}^{-}$ is displaced by ${}^{-}OH$, the same compound on the right is obtained.

Likewise,


Note that whichever $B{r}^{-}$ is displaced by ${}^{-}OH$, the same compound on the right is obtained..