Question

An organic compound (A) on ozonolysis followed by treatment with Zn dust and water gives product P, which can be used to preserve biological specimens. Identify A.

• A. 1
• B. 2
• C. 3
• D. 4

Hint:

Ethene is the simplest alkene. On ozonolysis followed by reductive workup \((Zn/H_2O)\), it yields two molecules of methanal \((HCHO)\), whose aqueous solution (formalin) is used for preserving biological specimens.

Answer 1

The Correct Option is C

Step 1: Match formalin to its ozonolysis precursor.
Formalin is aqueous HCHO. Only ethene (CH₂=CH₂) yields exclusively methanal upon reductive ozonolysis. Tetramethylethylene gives acetone, 2-butene gives ethanal, and cyclohexene gives a dialdehyde.

Step 2: Final Answer:
CH₂=CH₂ (option 3).