JEE Main20265 April 2026Morning ShiftChemistryAlcohols Phenols and EthersActual
Consider compounds A, B and C with following structural formulae A = CH₃ - CH₂ - CH₂ - CH₂ - CH₂ - OH B = CH₂ = CH - CH₂ - CH₂ - CH₃ C = HO - CH₂ - CH₂ - CH(OH) - CH₃ For the conversion of B from A, reagent (D) required is _________ and structural formula of product (E) obtained when C undergoes same reaction using excess reagent (D) is _________.
Options
- AD E Conc. H₂ SO₄ CH₂ = CH - CH(OH)CH₃
- BD E PCC HO - C H₂- CH₂- CH = CH₂
- CD E PCC CH₂ = CH - CH = CH₂
- DD E Conc. H₂ SO₄ or H₃ PO₄ CH₂ = CH - CH = CH₂
Correct answer
D. D E Conc. H₂ SO₄ or H₃ PO₄ CH₂ = CH - CH = CH₂
Step-by-step solution
Compound A is pentan-1-ol ( CH₃-CH₂-CH₂-CH₂-CH₂-OH ) and Compound B is pent-1-ene ( CH₂=CH-CH₂-CH₂-CH₃ ). The conversion of an alcohol to an alkene is a dehydration reaction, which requires an acidic dehydrating agent such as concentrated H₂SO₄ or H₃PO₄ . Thus, reagent D is concentrated H₂SO₄ or H₃PO₄ . Compound C is butane-1,3-diol ( HO-CH₂-CH₂-CH(OH)-CH₃ ). When C is treated with excess dehydrating agent (reagent D), both hydroxyl groups undergo elimination (dehydration). The elimination of two water molecules yi