Question

One mole of an alkene on ozonolysis gives one mole of propanal and one mole of pent-3-one. The alkene is

• A. 3-ethylpent-2-ene
• B. 4-ethylhex-3-ene
• C. 2-methylpropene
• D. 3-ethylhex-2-ene
• E. 3-ethylhexene

Hint:

To reconstruct alkene from ozonolysis products, join the two carbonyl carbons with a double bond.

Answer 1

The Correct Option is B

Concept:
Ozonolysis breaks the double bond of an alkene and converts each double bonded carbon into carbonyl compounds.
Step 1: Write the products.
Products formed are: \[ \text{Propanal } (CH_3CH_2CHO) \] and \[ \text{Pent-3-one } (CH_3CH_2COCH_2CH_3) \]
Step 2: Locate carbonyl carbons.
During ozonolysis, the carbonyl carbons were originally connected by a double bond in the alkene.
Step 3: Join both fragments.
Removing oxygen and joining carbonyl carbons: \[ CH_3CH_2CH = C(CH_2CH_3)_2 \] This corresponds to: \[ \text{4-ethylhex-3-ene} \]
Step 4: Final answer.
\[ \boxed{\text{4-ethylhex-3-ene}} \]
Hence, correct option is (B).