11.
Phenol reacts with methyl chloroformate in the presence of $$NaOH$$ to form product $$A.$$ $$A$$ reacts with $$B{r_2}$$ to form product $$B.$$ $$A$$ and $$B$$ are respectively :
This reaction is known as cannizzaro’s reaction. In this reaction benzaldehyde in presence of 50%. $$NaOH$$ undergoes disproportionation reaction and form one mol of Benzyl alcohol (Red. product) and one mole of
sod. benzoate (ox. product)
13.
Which of the following gives ethanal $$C{H_3}CHO$$ on acid hydrolysis ?
Aldol condensation in aldehydes is due to presence of $$\alpha $$ - hydiogen atoms. Those aldehydes which does not have $$\alpha $$ - hydrogen atom like $$HCHO,$$ does not give aldol condensation reaction.
18.
Compounds $$(A)$$ and $$(C)$$ in the following reactions are
\[C{H_3}CHO\xrightarrow[{\left( {{\text{ii}}} \right)\,{H_2}O}]{{\left( {\text{i}} \right)\,C{H_3}MgBr}}\left( A \right)\] \[\xrightarrow{{{H_2}S{O_4},\,\Delta }}\left( B \right)\] \[\xrightarrow{{{\text{Hydroboration oxidation}}}}\left( C \right)\]
19.
The major product of the following reaction sequence is \[\xrightarrow[\left( \text{ii} \right)\frac{HCHO}{{{H}^{+}}\left( \text{catalytic}\,\,\text{amount} \right)}]{\left( \text{i} \right)\frac{HCHO\,\left( \text{excess} \right)}{NaOH,\,\text{heat}}}\]