The major product X and Y formed in the following reaction sequence are cis - stilbene [C₆H₁₂]hν [air]I₂ Y · ABC26OR0579
Subject: Organic Chemistry · Chapter: Pericyclic Reactions · Topic: Pericyclic Reactions – General · Exam: GATE 2000-2022 · Marks: 2 · Difficulty: Medium
The major product X and Y formed in the following reaction sequence are
\[ \text{cis - stilbene} \xrightarrow[\mathrm{C_6H_{12}}]{h\nu} \xrightarrow[\text{air}]{\mathrm{I_2}} \mathrm{Y} \]
(a)$\mathrm{X}=$ 
$\mathrm{Y}=$ 
$\mathrm{Y}=$ (b)$\mathrm{X}=$ 
$\mathrm{Y}=$ 
$\mathrm{Y}=$ (c)$\mathrm{X}=$ 
$\mathrm{Y}=$ 
$\mathrm{Y}=$ (d)$\mathrm{X}=$ 
$\mathrm{Y}=$ 
$\mathrm{Y}=$ Answer
Answer: A ✓ checked by 4AB · confidence high
Explanation
cis-Stilbene undergoes photochemical (conrotatory) 6π electrocyclisation to trans-4a,4b-dihydrophenanthrene (X); I₂/air dehydrogenates it to phenanthrene (Y) — (a).
Study loop for Pericyclic Reactions