Which one of the following compound will be least susceptible to elimination of hydrogen bromide ?
(1) Br-CH₂-CH₂-NO₂

(2) Br-CH₂-CH₂-CH3

(3) Br-CH₂-CH₂-CN

(4) Br-CH₂-CH₂-Co₂Et

 

Two alkenes, X(91% yield) and Y(9% yield) are formed when the following compound is heated.

The structures of X and Y, respectively are:

1. 

2. 

3. 

4. 

In the dehydrohalogenation of 2-bromobutane; which conformation leads to the formation of cis-2-butene ?

(1)

(2)

(3)

(4)

$\begin{array}{ccccccc}{\mathrm{CH}}_3& -& \underset{\mathrm{Br}}{\underset{|}{\stackrel{\mathrm{Br}}{\stackrel{|}{\mathrm{C}}}}}& -& \stackrel{\mathrm{Br}}{\stackrel{|}{\underset{\mathrm{Br}}{\underset{|}{\mathrm{C}}}}}& -& {\mathrm{CH}}_3\end{array}$$\stackrel{{\mathrm{xNaNH}}_2}{\to }\stackrel{{\mathrm{yCH}}_3\mathrm{l}}{\to }$CH₃-C$\equiv \mathrm{C}-\mathrm{C}\equiv$C-CH₃

x and y mole consumed.

Value of x + y =

1. 5

2. 6

3. 7

4. 8

Identify A:-

1.		2.
3.		4.

$\underset{\mathrm{EtOH},∆}{\overset{\mathrm{KOH}}{\to }}\underset{\left(major\right)}{\left(A\right)}$

Product (A) is:

1.

2.

3.

4.

Br                  Br
 l                    l   
CH2-CH=CH-CH2→(A)
                       Zn(dust)

Above reaction is an example of 1,4-elimination.Predict the product.
(1) CH₃-CH=C=CH₂
(2) CH₃-C$\equiv$C-CH₃
(3) CH₃-CH₂-C$\equiv$CH
(4) H₂C=CH-CH=CH₂

Which is the major product expected from the following S_N² reaction?

1.      

2.     

3.     

4.    

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$<mspace\; width="1em"></mspace><mspace\; width="1em"></mspace><mspace\; width="1em"></mspace><mspace\; width="1em"></mspace><mspace\; width="1em"></mspace><mspace\; width="1em"></mspace><mspace\; width="1em"></mspace><mspace\; width="1em"></mspace><mspace\; width="1em"></mspace><mspace\; width="1em"></mspace><mspace\; width="1em"></mspace>|$
$C{H}_3—C—C{H}_3$
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$<mspace\; width="1em"></mspace><mspace\; width="1em"></mspace><mspace\; width="1em"></mspace><mspace\; width="1em"></mspace><mspace\; width="1em"></mspace><mspace\; width="1em"></mspace><mspace\; width="1em"></mspace><mspace\; width="1em"></mspace><mspace\; width="1em"></mspace><mspace\; width="1em"></mspace>Br$
        (a)

CH₃-CH-CH₃
         l
        Br
        (b)   

CH₃-CH-Br     
       (c)

Compare rate of E₂ reaction:-
(1)c>b>a

(2)a>b>c

(3)b>a>c

(4)c>a>b