Either t-butyl alcohol or isobutylene treated with strong sulfuric acid and. hydrogen peroxide gives a mixture of two liquid compounds (A and B), the ratio of which depends on whether the hydrogen peroxide or organic starting material is in excess. Both substances are reasonably stable and \(\mathrm{A}\) is \(\mathrm{C}_{4} \mathrm{H}_{10} \mathrm{O}_{2}\), whereas B is \(\mathrm{C}_{8} \mathrm{H}_{10} \mathrm{O}_{2}\). Treatment of \(\mathrm{A}\) and \(\mathrm{B}\) with hydrogen over a nickel catalyst results in quantitative conversion of each compound to t-butyl alcohol. A reacts with acyl halides and acid anhydrides, whereas \(\mathrm{B}\) is unaffected by these reagents. Treatment of 1 mole of \(\mathrm{A}\) with excess methylmagnesium iodide in diethyl ether solution produces 1 mole of methane and 1 mole each of t-butyl alcohol and methanol. One mole of \(B\) with excess methylmagnesium iodide gives 1 mole of methy1 t-butyl ether and 1 mole of t-buty1 alcohol. When \(B\) is heated with vinyl chloride it causes polymerization to occur. Work out structures for \(\mathrm{A}\) and \(\mathrm{B}\) from the above data. Write equations for all the reactions involved, showing the mechanisms and intermediates that are important for each.

Step by step solution

01

1. Analyze compound A properties

Molecular formula: \(\mathrm{C}_{4} \mathrm{H}_{10} \mathrm{O}_{2}\) When treated with hydrogen over a nickel catalyst, it is converted to t-butyl alcohol. Reacts with acyl halides and acid anhydrides. When treated with excess methylmagnesium iodide in diethyl ether solution, it produces one mole of methane, one mole of t-butyl alcohol and one mole of methanol.

02

2. Deduce structure of compound A

From the information about its reaction with methylmagnesium iodide, we can deduce that compound A contains an ester group, as it produces methanol, methane, and t-butyl alcohol. Thus, we can find the structure as follows: \(\mathrm{C}_{4} \mathrm{H}_{10} \mathrm{O}_{2}\) has 2 oxygen atoms (from the ester group), which means the rest of the structure needs to account for 3 carbons and 8 hydrogens. The t-butyl group present in the resulting t-butyl alcohol implies that compound A is an ester of t-butyl alcohol when reacted with methylmagnesium iodide. Therefore, compound A has the structure of t-butyl methanoate: (CH\(_3\))\(_3\)C-O-C(O)CH\(_3\)

03

3. Analyze compound B properties

Molecular formula: \(\mathrm{C}_{8} \mathrm{H}_{10} \mathrm{O}_{2}\) When treated with hydrogen over a nickel catalyst, it is quantitatively converted to t-butyl alcohol. It's unaffected by acyl halides and acid anhydrides. When treated with excess methylmagnesium iodide, it gives one mole of methyl t-butyl ether and one mole of t-butyl alcohol. Polymerizes when heated with vinyl chloride.

04

4. Deduce structure of compound B

The reactivity pattern for compound B suggests that it's a tertiary carboxylic acid with a t-butyl group. The molecular formula implies we need to account for 4 carbons and 6 hydrogens for the rest of the structure. Based on this information and its reaction with methylmagnesium iodide, compound B has the structure of t-butyl peroxiisobutyrate: (CH\(_3\))\(_3\)C-O-O-C(O)(CH\(_3\))\(_2\)

05

5. Write equations for the reactions

For compound A: 1. Reduction to t-butyl alcohol: (CH\(_3\))\(_3\)C-O-C(O)CH\(_3\) + H\(_2\) (Ni catalyst) \(\rightarrow\) (CH\(_3\))\(_3\)COH + CH\(_3\)OH 2. Reaction with acyl halides and acid anhydrides will follow esterification. 3. Reaction with methylmagnesium iodide: \[\text{t-Butyl methanoate} +\text{MeMgI} \rightarrow \text{t-Butyl alcohol} + \text{methanol} +\text{methane}\] For compound B: 1. Reduction to t-butyl alcohol: (CH\(_3\))\(_3\)C-O-O-C(O)(CH\(_3\))\(_2\) + H\(_2\) (Ni catalyst) \(\rightarrow\) 2 (CH\(_3\))\(_3\)COH 2. Unaffected by acyl halides and acid anhydrides. 3. Reaction with methylmagnesium iodide: \[\text{t-Butyl peroxiisobutyrate} +\text{MeMgI} \rightarrow \text{t-Butyl alcohol} +\text{methyl t-butyl ether}\] 4. Polymerization with vinyl chloride will follow radical polymerization.

Unlock Step-by-Step Solutions & Ace Your Exams!

• Full Textbook Solutions

  Get detailed explanations and key concepts

• Unlimited Al creation

  Al flashcards, explanations, exams and more...

• Ads-free access

  To over 500 millions flashcards

• Money-back guarantee

  We refund you if you fail your exam.

Start your free trial

Over 30 million students worldwide already upgrade their learning with Vaia!