In the two setp reaction sequence given below, the starting bis - sulfone acts as + heat · ABC26OR0582
Subject: Organic Chemistry · Chapter: Pericyclic Reactions · Topic: Cycloaddition Diels Alder · Exam: GATE 2000-2022 · Marks: 2 · Difficulty: Medium
In the two setp reaction sequence given below, the starting bis - sulfone acts as 
$+$ 
heat 
$+$ heat (a)a dienophile and synthetic equivalent of acetylene
(b)a dienophile and synthetic equivalent of ethylene
(c)a dipolarophile and synthetic equivalent of acetylene
(d)a dipolarophile and synthetic equivalent of ethylene
Answer
Answer: A ✓ checked by 4AB · confidence medium
The source book printed D; on checking, A is correct — see the explanation.
Book printed (d).
Explanation
The bis-sulfone alkene is the dienophile; Na/Hg then eliminates both PhSO₂ groups to create a C=C, so the reagent is a synthetic equivalent of acetylene (a).
Study loop for Pericyclic Reactions