Question

One mole of an alkene on ozonolysis gives a mixture of one mole pentan-3-one and one mole methanal. The alkene is:

• A. 3-ethylbut-1-ene
• B. 2-methylpent-1-ene
• C. 2-ethylbut-1-ene
• D. 4-methylpent-1-ene
• E. 4-methylpent-2-ene

Hint:

Ozonolysis is a useful reaction to determine the structure of alkenes by analyzing the carbonyl products formed.

Answer 1

The Correct Option is C

Ozonolysis cleaves the double bond in an alkene, producing two carbonyl compounds. The given products, pentan-3-one and methanal, suggest that the original alkene had its double bond positioned such that these fragments would result. 
By analyzing the structure, the correct alkene is 2-ethylbut-1-ene, which when ozonized, splits at the C=C bond to form the given products.