Question

Explain how to do the transition state of the reaction between 1-butanol and sodium bromide

Answer 1

The reaction of 1-butanol with NaBr is generally donw in the presence of an acid to finally get 1- Bromobutane. H+ H2H2 H2c OH Na Br H3C o Br H2 C HO The acid first protonates the -OH group of 1-butanol as follows: Hac он, OH HC - H2 Now. Br-from NaBr acts as a nucleophile and attacks the electrophilic Catom with the leaving group OH It happens via the SN2 (Second Order nucleophilic substitution) mechanism as the substrate is freeof steric strain and since formation of primary carbocation is not favored. The formation of the transition state and product can be shown as follows: Note that the attack of the nucleophile happens from the opposite side of the leaving group. - OH Br------------OH * Hac CH2 HC CH2 H2C Transition state of SN2 mechanism C-Br bond forms C-OH2 bond breaks Hн Br—C H₂C Product) H₂C-CH₂

Note: Only thing to keep in mind here is to make the nucleophile attack from the opposite side of the leaving group.