Cyclohexene can be converted to 1-cyclopentenecarbaldehyde by the following series of reactions. Propose a structural formula for each intermediate compound.

Question: Outline the steps involved in converting cyclohexene to 1-cyclopentenecarbaldehyde and the intermediate structures formed during this process. Answer: The conversion of cyclohexene to 1-cyclopentenecarbaldehyde involves the following steps: 1. Oxidation of the double bond using ozonolysis (ozone and dimethyl sulfide or zinc) to form carbonyl groups (C1=O and C6=O) on former double-bonded carbons. 2. Reductive removal of the C6=O carbonyl group using Wolff-Kishner reduction (hydrazine and potassium hydroxide) to create a methylene group (C6=CH2). 3. Formation of the aldehyde functional group (H-C=O) at position C1 by DIBAL-H reduction. The intermediate structures are: (1) C1=O and C6=O, (2) C1=O and C6=CH2. The final product is 1-cyclopentenecarbaldehyde with C1=(H-C=O) and C5=CH2.