Question
$$But$$ $$-2-ene$$ exhibits $$cis-trans-isomerism$$ due
to
A.
rotation around $${C_2} - {C_3}$$ double bond
B.
rotation around $${C_3} - {C_4}$$ sigma bond
C.
rotation around $${C_1} - {C_2}$$ bond
D.
restricted rotation around $$C=C$$ bond
Answer :
restricted rotation around $$C=C$$ bond
Solution :
Due to presence of $$ > C = C < $$ in $$but$$ $$-2-ene,$$ it shows restricted rotation. Hence, give two types of arrangements around the space of $$ > C = C < $$ as $$cis$$ and $$trans$$ - forms.