Question

An alkene ‘A’ (Mol. formula C₅H₁₀) on ozonolysis gives a mixture of two compounds ‘B’ and ‘C’. Compound ‘B’ gives positive Fehling’s test and also forms iodoform on treatment with I₂ and NaOH. Compound ‘C’ does not give Fehling’s test but forms iodoform. Identify the compounds A, B and C. Write the reaction for ozonolysis and formation of iodoform from B and C.

Answer 1

Compound A is an alkene, on ozonolysis it will give carbonyl compounds. As both B and C have > C=O group,

B gives positive Fehling’s test so it is an aldehyde and it gives iodoform test so it is so it has CH₃C=O group.

This means the aldehyde is acetaldehyde C does not give Fehling’s test, so it is a ketone. It gives positive iodoform test so it is a methyl ketone means it has CH₃C=O group

Compound A (C₅H₁₀) on ozonlysis gives B (CH₃CHO) + C (CH₃COR)

So “C” is CH₃COCH₃

A = CH₃CH=C(CH₃)₂

B = CH₃CHO

C = CH₃COCH₃