Question

How is the following conversion effected phenyl methanal into benzoin?

Answer 1

$$\begin{array}{c}\underset{\mathrm{Phenyl}\mathrm{methanal}}{\mathrm{C}{\phantom{A}}_6\mathrm{H}{\phantom{A}}_5\mathrm{CHO}+}\mathrm{C}{\phantom{A}}_6\mathrm{H}{\phantom{A}}_5\mathrm{CHO}\underset{\mathrm{KCN}}{\overset{\mathrm{alc}}{\to }}\mathrm{C}{\phantom{A}}_6\mathrm{H}{\phantom{A}}_5-\mathrm{CH}-\mathrm{C}-\mathrm{C}{\phantom{A}}_6\mathrm{H}{\phantom{A}}_5\\ \phantom{.........................................}|\phantom{....}||\phantom{}\\ \phantom{.......................................}\underset{(\mathrm{Benzoin})}{\mathrm{OH}}\phantom{}\mathrm{O}\phantom{}\end{array}$$