181. The $$C-O-C$$ angle in ether is about
A
$${180^ \circ }$$
B
$${190^ \circ }28'$$
C
$${110^ \circ }$$
D
$${105^ \circ }$$
Answer :
$${110^ \circ }$$
183. Williamson synthesis of ether is an example of :
A
Nucleophilic addition
B
Electrophilic addition
C
Electrophilic substitution
D
Nucleophilic substitution
Answer :
Nucleophilic substitution
184.
In the following reactions,
\[\left( \text{i} \right)C{{H}_{3}}\overset{\begin{smallmatrix}
\,\,C{{H}_{3}} \\
|\,\,\,\,
\end{smallmatrix}}{\mathop{-CH-}}\,\underset{\begin{smallmatrix}
|\,\,\,\,\,\,\,\,\,\,\, \\
OH\,\,\,\,\,\,\,\,
\end{smallmatrix}}{\mathop{CH-}}\,C{{H}_{3}}\] \[\xrightarrow{\frac{{{H}^{+}}}{\text{heat}}}\underset{\left[ \begin{smallmatrix}
\text{Major} \\
\text{product}
\end{smallmatrix} \right]}{\mathop{A}}\,+\underset{\left[ \begin{smallmatrix}
\text{Minor} \\
\text{product}
\end{smallmatrix} \right]}{\mathop{B}}\,\]
\[\left( \text{ii} \right)A\xrightarrow[\text{in absence of peroxide }]{HBr,\,\text{dark}}\] \[\underset{\left[ \begin{smallmatrix}
\text{Major} \\
\text{product}
\end{smallmatrix} \right]}{\mathop{C}}\,+\underset{\left[ \begin{smallmatrix}
\text{Minor} \\
\text{product}
\end{smallmatrix} \right]}{\mathop{D}}\,\]
The major products $$A$$ and $$C$$ are respectively
A
\[C{{H}_{2}}=\overset{\begin{smallmatrix}
\,\,C{{H}_{3}} \\
|\,\,\,
\end{smallmatrix}}{\mathop{C-}}\,C{{H}_{2}}-C{{H}_{3}}\,\,\text{and}\] \[\underset{\begin{smallmatrix}
|\,\,\,\,\,\,\,\,\,\,\,\,\, \\
Br\,\,\,\,\,\,\,\,\,\,\,\,
\end{smallmatrix}}{\mathop{C{{H}_{2}}-}}\,\overset{\begin{smallmatrix}
C{{H}_{3}}\,\, \\
|\,\,\,\,\,\,\,\,
\end{smallmatrix}}{\mathop{CH-}}\,C{{H}_{2}}-C{{H}_{3}}\]
B
\[C{{H}_{3}}\overset{\begin{smallmatrix}
\,\,\,\,\,C{{H}_{3}} \\
|
\end{smallmatrix}}{\mathop{-C=}}\,CH-C{{H}_{3}}\,\,\text{and}\] \[C{{H}_{3}}\underset{\begin{smallmatrix}
| \\
Br
\end{smallmatrix}}{\overset{\begin{smallmatrix}
\,\,\,\,\,\,C{{H}_{3}} \\
\,|
\end{smallmatrix}}{\mathop{-C-}}}\,C{{H}_{2}}-C{{H}_{3}}\]
C
\[C{{H}_{3}}\overset{\begin{smallmatrix}
\,\,\,\,\,C{{H}_{3}} \\
|
\end{smallmatrix}}{\mathop{-C=}}\,CH-C{{H}_{3}}\,\,\text{and}\] \[C{{H}_{3}}\overset{\begin{smallmatrix}
\,\,\,C{{H}_{3}} \\
|\,\,\,
\end{smallmatrix}}{\mathop{-CH-}}\,\underset{\begin{smallmatrix}
|\,\,\,\,\,\,\,\,\,\,\,\, \\
Br\,\,\,\,\,\,\,\,\,\,\,
\end{smallmatrix}}{\mathop{CH-}}\,C{{H}_{3}}\]
D
\[C{{H}_{2}}\overset{\begin{smallmatrix}
\,\,\,\,\,\,\,\,C{{H}_{3}} \\
\,\,\,|
\end{smallmatrix}}{\mathop{=C-}}\,C{{H}_{2}}-C{{H}_{3}}\,\,\text{and}\] \[C{{H}_{3}}\underset{\begin{smallmatrix}
| \\
Br
\end{smallmatrix}}{\overset{\begin{smallmatrix}
\,\,\,\,\,\,C{{H}_{3}} \\
\,|
\end{smallmatrix}}{\mathop{-C-}}}\,C{{H}_{2}}-C{{H}_{3}}\]
Answer :
\[C{{H}_{3}}\overset{\begin{smallmatrix}
\,\,\,\,\,C{{H}_{3}} \\
|
\end{smallmatrix}}{\mathop{-C=}}\,CH-C{{H}_{3}}\,\,\text{and}\] \[C{{H}_{3}}\underset{\begin{smallmatrix}
| \\
Br
\end{smallmatrix}}{\overset{\begin{smallmatrix}
\,\,\,\,\,\,C{{H}_{3}} \\
\,|
\end{smallmatrix}}{\mathop{-C-}}}\,C{{H}_{2}}-C{{H}_{3}}\]
186. The structure of the compound that gives a tribromo derivative on treatment with bromine water is
A
B
C
D
Answer :
187. $$HBr$$ reacts with $$C{H_2} = CH - OC{H_3}$$ under anhydrous conditions at room temperature to give
A
$$BrC{H_2} - C{H_2} - OC{H_3}$$
B
$${H_3}C - CHBr - OC{H_3}$$
C
$$C{H_3}CHO\,{\text{and}}\,C{H_3}Br$$
D
$$BrC{H_2}CHO\,\,{\text{and}}\,C{H_3}OH$$
Answer :
$${H_3}C - CHBr - OC{H_3}$$
188.
Which of the following are intermediates in the reaction of excess of \[C{{H}_{3}}MgBr\] with \[{{C}_{6}}{{H}_{5}}COO{{C}_{2}}{{H}_{5}}\] to make 2 - phenyl - 2 - propanol ?
A
A and B
B
A, B and C
C
A and C
D
B and C
Answer :
A, B and C
189.
The following change can be carried out with
A
$$NaB{H_4}$$
B
$$LiAl{H_4}$$
C
$${H_2}/Pt$$
D
$$PCC/C{H_2}C{l_2}$$
Answer :
$$LiAl{H_4}$$
190.
In the following sequence of reactions,
\[C{{H}_{3}}C{{H}_{2}}OH\xrightarrow{P+{{I}_{2}}}A\xrightarrow[\text{ether}]{Mg}\] \[B\xrightarrow{HCHO}C\xrightarrow{{{H}_{2}}O}D\]
the compound $$D$$ is
A
propanal
B
butanal
C
$$n$$ - butyl alcohol
D
$$n$$ - propyl alcohol
Answer :
$$n$$ - propyl alcohol
