Two different ways to convert 2-methylbut-2-ene to 3-bromo-2-methylbutan-2-ol are to be shown. Concept introduction: When alkene reacts with molecular bromine in carbon tetrachloride as a solvent, vicinal dibromide is formed. But, when the same reaction is carried out in the water as the solvent, addition of Br and OH across the double bond takes place. In this reaction, the first step is the formation of the bromonium ion intermediate. The bromonium ion is then attacked by water rather than the bromide ion because the concentration of water is much higher. The attack by water takes place at the more substituted carbon, opening up the bromonium and forming a protonated alcohol. The uncharged alcohol is formed by deprotonation. Alkene, on treatment with peracids, forms an epoxide . The epoxide adds bromine at the less substituted carbon with ring-opening on treatment with NaBr under neutral conditions. Acid workup gives the corresponding alcohol.

Question

Want to see the full answer?

Answer 1

Question

Chapter 12, Problem 12.64P

Interpretation Introduction

Interpretation:

Two different ways to convert 2-methylbut-2-ene to 3-bromo-2-methylbutan-2-ol are to be shown.

Concept introduction:

When alkene reacts with molecular bromine in carbon tetrachloride as a solvent, vicinal dibromide is formed. But, when the same reaction is carried out in the water as the solvent, addition of Br and OH across the double bond takes place. In this reaction, the first step is the formation of the bromonium ion intermediate. The bromonium ion is then attacked by water rather than the bromide ion because the concentration of water is much higher.

The attack by water takes place at the more substituted carbon, opening up the bromonium and forming a protonated alcohol. The uncharged alcohol is formed by deprotonation.

Alkene, on treatment with peracids, forms an epoxide. The epoxide adds bromine at the less substituted carbon with ring-opening on treatment with NaBr under neutral conditions. Acid workup gives the corresponding alcohol.

Expert Solution & Answer

Want to see the full answer?

Check out a sample textbook solution

See solution

Students have asked these similar questions

I need help with the following question

For CARS, which statement is not true regarding its advantages? a) Contrast signal based on vibrational characteristics, no need for fluorescent tagging. b) Stronger signals than spontaneous Raman. c) Suffers from fluorescence interference, because CARS signal is at high frequency. d) Faster, more efficient imaging for real-time analysis. e) Higher resolution than spontaneous Raman microscopy.

Draw the major product of the Claisen condensation reaction between two molecules of this ester. Ignore inorganic byproducts. Incorrect, 5 attempts remaining 1. NaOCH3/CH3OH 2. Acidic workup Select to Draw O Incorrect, 5 attempts remaining The total number of carbons in the parent chain is incorrect. Review the reaction conditions including starting materials and/or intermediate structures and recount the number of carbon atoms in the parent chain of your structure. OK