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Question: Isobutyl magnesium bromide with dry ether and absolute alcohol gives: A.\(\ C{H_3} - CH - C{H_...

Isobutyl magnesium bromide with dry ether and absolute alcohol gives:
A. CH3−CH−CH2OH               ∣              CH3  \ C{H_3} - CH - C{H_2}OH \\\ \,\,\,\,\,\,\,\,\,\,\,\,\,\,| \\\ \,\,\,\,\,\,\,\,\,\,\,\,\,C{H_3} \\\ \ and CH3CH2MgBrC{H_3}C{H_2}MgBr
B.  CH3−CH−CH2−CH3                 ∣               CH3  \ C{H_3} - CH - C{H_2} - C{H_{3\,}} \\\ \,\,\,\,\,\,\,\,\,\,\,\,\,\,\,| \\\ \,\,\,\,\,\,\,\,\,\,\,\,\,\,C{H_3} \\\ \ and Mg(OH)BrMg(OH)Br
C.  CH3−CH−CH3CH2−CH2                  ∣                 CH3               \ C{H_3} - CH - C{H_3}CH2 - C{H_{2\,}} \\\ \,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,| \\\ \,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,C{H_3} \\\ \,\,\,\,\,\,\,\,\,\,\,\, \\\ \ and Mg(OH)BrMg\left( {OH} \right)Br
D.  CH3−CH−CH3                 ∣                CH3  \ C{H_{_3}} - CH - C{H_3} \\\ \,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,| \\\ \,\,\,\,\,\,\,\,\,\,\,\,\,\,\,C{H_3} \\\ \ and CH3CH2OMgBrC{H_3}C{H_2}OMgBr

Explanation

Solution

The compounds having a generic formula of R−Mg−XR - Mg - X where XX is the halogen and RR is usually an alkyl or aryl group is called Grignard reagent of Grignard compound. In organic synthesis Grignard reagent is popular in the synthesis of new carbon - carbon bonds.

Complete step by step answer:
In this reaction isobutyl magnesium bromide reacts with absolute alcohol where isobutyl magnesium bromide acts as Grignard reagent and reacts with absolute alcohol. Here Grignard reagents react with the active hydrogen present in absolute alcohol. During this reaction the active hydrogen present in the absolute alcohol gets swapped with MgBrMgBr present in isobutyl magnesium bromide forming isobutane and magnesium bromide ethanoate as the end products.

Hence, we get the final products isobutane and magnesium bromide ethanoate.

So, the correct answer is Option D.

Additional information:
Pure Grignard reagents are extremely reactive solids hence they are usually handled as solutions in solvents like diethyl ether or tetrahydrofuran which are stable as long as water is excluded. In those mediums Grignard reagent is invariably present as a complex along with magnesium atoms connected with two ether oxygens by means of coordination bonds.

Note: Grignard reagents are prepared by treating organic handles (normally organo bromine) with magnesium metal. In order to stabilize organo magnesium compounds cyclic or acyclic ethers are used. Water and air rapidly destroys the reagent by protonolysis or oxidation are excluded using air free techniques.