Question

A hydrocarbon (A) with molecular formula C₅H₁₀ on ozonolysis gives two products (B) and (C). Both (B) and (C) give a yellow precipitate when heated with iodine in presence of NaOH while only (B) give a silver mirror on reaction with Tollen’s reagent.

1. Identify (A), (B) and (C).
2. Write the reaction of B with Tollen’s reagent.
3. Write the equation for iodoform test for C.
4. Write down the equation for aldol condensation reaction of B and C.

Answer 1

a. A is an alkene.

B is an aldehyde with –CH₃ group.

C is a methyl ketone.

b. \[\ce{CH3CHO + [Ag(NH3)2]^{+} + OH^{-} -> CH3COO^{-} + Ag + NH3 + H2O}\]

c. \[\ce{CH3COCH3 + NaOH + I2 -> CHl3 + CH3COONa}\]

d. A: CH(CH₃) = C(CH₃)₂, B: CH₃CHO, C: O = C(CH₃)₂

\[\begin{array}{cc}
\ce{CH3COCH3 + CH3CHO}\phantom{............................................................................}\\
\ce{↓ Ba(OH)2}\phantom{.....................................................................}\\
\phantom{}\ce{(CH3)2C(OH)CH2COCH3 + CH3CH(OH)CH2CHO + (CH3)2C(OH)CH2CHO + CH3CH(OH)CH2COCH3}\\
\ce{↓ Heat}\phantom{.........................................................................}\\
\ce{(CH3)2C = CHCOCH3 + CH3CH = CHCHO + (CH3)2C = CHCHO + CH3CH = CHCOCH3}\phantom{............}
\end{array}\]