Question

2. The addition of HBr to 2-methylpropene can, in principle, give either 1-bromo-2- methylpropane or 2-bromo-2-methylpropane. In reality, only the latter is formed. Show mechanisms for the formation of each of these alkyl bromides, using curved arrows to indicate the flow of electron pairs. Also, construct reaction energy diagrams that describe the energy of the system as a function of the progress in formation of both alkyl bromides. Use these reaction coordinate diagrams to explain why 2-bromo-2-methylpropane is the only product.

Answer 1

[Answers Reach.com F + HBr Br + YBr Formed Not Formed Mechanism The electrophilic addihools HBT to 2-methyl- Poopene Proceeding through the carbocahºm intermediate. Home - Broj jo tyo 3° carbocahom More stable i carbocation less stable your se Youth for YB 2-met e on addition of HBr to gives mixture of two Carbocahon. The gº carbocahom and 1° carbocah com Loomed: The gº carbocahom is more stable than 10 carbocahºo7. The 30 carbocahon is stabilized by electocom domaning induchve elsech of three methyl group and g-hyper conjugahve structure. on other hand to carbocahon is less stable.because it is Stabilized by only one hyper conjugative structure. There luo clue to higher stability of 30 carbocahom it required lower energy ols achvalio bor loomalism and it Fasler boomed in higher Proposhºors. The 10 carbocahon is less stable and it required higher energy ols ach vation and it slowly boomed. and it's too Proportion is very low.

Reach or Energy Diagram Met AE2>> DEI DEL AF me me me 1 my = +HA +HBO me CHEÇ-Br сқ 'Reachion coordinate! The teachen coordinate diagram show that loo the Lormabon 055 3º Carbocahon (@EI), the energy required to form thi's Carbocahon is very lower than the energy required Lorm the 1° carbocahoon (AE2). Therelore, due to higher stability of 3º Carbocahon it required lower energy olb achºvah (DELJ and it Faster Loomed in high proportion. On other hand the energy required to Loom 1° carbocahim is very higher because it is less stable and it slowly comed and it's Proportion is very low. These love 2-methyl Propene, on addih om os H138 gives only 2-bromo-2-methyl Propane as single Product.