In a Diels-Alder reaction, the most reactive diene amongst the following is
(a)(4E)-1, 4-hexadiene
(b)(4Z)-1, 4-hexadiene
(c)(2E, 4E)-2, 4-hexadiene
(d)(2Z, 4Z)-2, 4-hexadiene
Answer
Answer: C ✓ checked by 4AB · confidence high
Explanation
Only conjugated dienes react; (2E,4E)-hexadiene adopts the s-cis conformation easily, whereas the (2Z,4Z) isomer suffers severe steric clash in s-cis. The 1,4-dienes are not conjugated.