Conjugated dienes and Diels-Alder reaction

34 questions on Conjugated dienes and Diels-Alder reaction from the Hydrocarbons chapter: 7 NEET level, 13 JEE Main, 14 JEE Advanced. Each one opens with its answer and solution.

• Which of the following is a conjugated diene? NEET level
• The Diels-Alder reaction of buta-1,3-diene with ethene gives NEET level
• Penta-1,3-diene is more stable than penta-1,4-diene mainly because of NEET level
• Buta-1,3-diene reacts with dimethyl fumarate (dimethyl (E)-but-2-enedioate). The Diels-Alder adduct is JEE Main level
• Buta-1,3-diene reacts with 1 mol of HBr at 40 degC under thermodynamic control. The major product is JEE Main level
• Which diene does NOT undergo the Diels-Alder reaction readily? JEE Main level
• Cyclohexa-1,3-diene is treated with O3 followed by Zn/H2O. The organic products are JEE Main level
• Which of the following dienophiles reacts fastest with buta-1,3-diene in a normal-electron-demand Diels-Alder reaction? JEE Main level
• 2,3-Dimethylbuta-1,3-diene reacts with propenal (CH2=CH-CHO) in a Diels-Alder reaction. The product is JEE Advanced level
• Which of the following can act as the diene component in a Diels-Alder reaction? Select all that apply. JEE Main level
• Isoprene (2-methylbuta-1,3-diene) is treated with 1 mol of HCl at low temperature under kinetic control. Assume that the allylic cation is captured by chloride ... JEE Advanced level
• For the addition of HBr to buta-1,3-diene, which of the following statements are correct? Select all that apply. JEE Advanced level
• Cyclopentadiene reacts with maleic anhydride at room temperature. Which of the following statements are correct? Select all that apply. JEE Advanced level
• Isoprene reacts with methyl acrylate (CH2=CH-CO2CH3) in a Diels-Alder reaction. Assume the major product is the 'para' (1,4) regioisomer, in which the methyl gr... JEE Advanced level
• Cyclohexa-1,3-diene reacts with one equivalent of HBr. The 1,2-adduct and the 1,4-adduct are best described as JEE Advanced level
• Buta-1,3-diene is heated with ethene to form a cyclic hydrocarbon Y. Y is oxidised with hot concentrated KMnO4 followed by acidification. The final organic prod... JEE Advanced level
• The number of sigma and pi bonds in buta-1,3-diene, CH2=CH-CH=CH2, is respectively: NEET level
• Which of the following is a conjugated diene? NEET level
• The Diels-Alder reaction between a conjugated diene and an alkene is classified as a: NEET level
• One mole of HBr adds to buta-1,3-diene at -80 degC (kinetic control). The major product is: NEET level
• For the addition of HBr to buta-1,3-diene, which statement is correct? JEE Main level
• Which of the following is the most reactive dienophile towards buta-1,3-diene in a Diels-Alder reaction? JEE Main level
• Cyclopenta-1,3-diene reacts with maleic anhydride at room temperature. The major (kinetic) product is: JEE Main level
• Buta-1,3-diene reacts with dimethyl fumarate (dimethyl (E)-but-2-enedioate) in a Diels-Alder reaction. The product is: JEE Main level
• Reductive ozonolysis (O3 then Zn/H2O) of cyclohexa-1,3-diene gives: JEE Main level
• Which of the following are conjugated dienes? JEE Main level
• Which of the following statements about the Diels-Alder reaction are correct? JEE Main level
• One mole of HBr adds to 2-methylbuta-1,3-diene (isoprene) at -80 degC under kinetic control, with no peroxide. Assume the more stable allylic cation is formed a... JEE Advanced level
• (2E,4Z)-Hexa-2,4-diene reacts with ethene in a Diels-Alder reaction (assume it reacts). The product, 3,6-dimethylcyclohexene, is: JEE Advanced level
• A hydrocarbon C6H10 undergoes a Diels-Alder reaction with maleic anhydride. Its reductive ozonolysis gives only methanal and butane-2,3-dione. The hydrocarbon i... JEE Advanced level
• The enthalpy of hydrogenation of but-1-ene to butane is -127 kJ mol^-1 and that of buta-1,3-diene to butane (2 mol H2) is -239 kJ mol^-1. The stabilisation ener... JEE Advanced level
• For the Diels-Alder adduct of cyclopenta-1,3-diene and maleic anhydride (bicyclo[2.2.1]hept-5-ene-2,3-dicarboxylic anhydride), which statements are correct? JEE Advanced level
• Assertion (A): 1,4-Addition of HBr to buta-1,3-diene is favoured at higher temperature (about 40 degC). Reason (R): The 1,4-adduct is formed faster than the 1,2... JEE Advanced level
• Cyclohex-3-ene-1-carbaldehyde is best prepared by a Diels-Alder reaction between: JEE Advanced level