Question

An organic compound A with molecular formula C₅H₁₂O undergoes iodoform reaction, reacts with PCC to form compound B. Compound A when reacts with Na metal evolves bubbles of H₂ gas. Identify the structure of compound B and write all chemical reactions involved.

Answer 1

Dear Student,

$$\begin{gathered} \mathrm{Compound}\mathrm{A}\mathrm{reacts}\mathrm{with}\mathrm{PCC}\mathrm{and}\mathrm{reacts}\mathrm{with}\mathrm{Na}\mathrm{metal}\mathrm{to}\mathrm{evolve}{\mathrm{H}}_2\mathrm{gas},\mathrm{therefore}\mathrm{it}\mathrm{should}\mathrm{be}\mathrm{an}\mathrm{alcohol}. \\ \mathrm{Also},\mathrm{it}\mathrm{shows}\mathrm{iodoform}\mathrm{reaction}\mathrm{and}\mathrm{this}\mathrm{indicates}\mathrm{the}\mathrm{presence}\mathrm{of}-\mathrm{C}\left(\mathrm{OH}\right){\mathrm{CH}}_3\mathrm{group}. \\ \mathrm{Therefore},\mathrm{compound}\mathrm{A}\mathrm{is}{\mathrm{CH}}_3{\mathrm{CH}}_2{\mathrm{CH}}_2\mathrm{CH}\left(\mathrm{OH}\right){\mathrm{CH}}_3 \\ {\mathrm{CH}}_3{\mathrm{CH}}_2{\mathrm{CH}}_2\mathrm{CH}\left(\mathrm{OH}\right){\mathrm{CH}}_3+{\mathrm{I}}_2+\hspace{0.17em}\mathrm{NaOH}\to {\mathrm{CHI}}_3+\hspace{0.17em}{\mathrm{CH}}_3{\mathrm{CH}}_2{\mathrm{CH}}_2{\mathrm{COO}}^{-}+{\mathrm{H}}_2\mathrm{O} \\ {\mathrm{CH}}_3{\mathrm{CH}}_2{\mathrm{CH}}_2\mathrm{CH}\left(\mathrm{OH}\right){\mathrm{CH}}_3+\mathrm{Na}\to {\mathrm{CH}}_3{\mathrm{CH}}_2{\mathrm{CH}}_2\mathrm{CH}\left({\mathrm{O}}^{-}{\mathrm{Na}}^{+}\right){\mathrm{CH}}_3+{\mathrm{H}}_2 \\ \mathrm{Now},\mathrm{PCC}\hspace{0.17em}\mathrm{oxidises}\mathrm{secondary}\mathrm{alcohols}\mathrm{to}\mathrm{ketones},\mathrm{therefore} \\ {\mathrm{CH}}_3{\mathrm{CH}}_2{\mathrm{CH}}_2\mathrm{CH}\left(\mathrm{OH}\right){\mathrm{CH}}_3\stackrel{\mathrm{PCC}}{\to }{\mathrm{CH}}_3{\mathrm{CH}}_2{\mathrm{CH}}_2{\mathrm{COCH}}_3 \\ \left(\mathrm{B}\right) \end{gathered}$$