Reaction of one molecule of HBr with one mole | vedclass

Name: Exam Paper Generator | JEE NEET Paper Generator | Vedclass
Brand: Vedclass
Rating: 5 (35 reviews)

Question

(B) The reaction of $1,3-$butadiene with $HBr$ produces two isomers: $3-$bromobutene ($1,2-$addition product) and $1-$bromo$-2-$butene ($1,4-$addition

Vedclass · Accepted Answer

$1-$bromo$-2-$butene under thermodynamically controlled conditions

Vedclass · Answer

(B) The reaction of $1,3-$butadiene with $HBr$ produces two isomers: $3-$bromobutene ($1,2-$addition product) and $1-$bromo$-2-$butene ($1,4-$addition product).At low temperatures (e.g.,$-80\,^{\circ}C$),the reaction is kinetically controlled,favoring the $1,2-$addition product ($3-$bromobutene) due to the proximity of the intermediate carbocation.At higher temperatures (e.g.,$40\,^{\circ}C$),the reaction is thermodynamically controlled,favoring the more stable $1,4-$addition product ($1-$bromo$-2-$butene) because the double bond in the $1,4-$product is more substituted and thus more stable.Therefore,at $40\,^{\circ}C$,$1-$bromo$-2-$butene is the major product.

Reaction of one molecule of $HBr$ with one molecule of $1,3-$butadiene at $40\,^{\circ}C$ gives predominantly

Similar Questions

$A$ hydrocarbon $C_6H_{10}$ absorbs only one molecule of $H_2$ upon catalytic hydrogenation. Upon ozonolysis,it yields $CHO(CH_2)_4CHO$. What is the hydrocarbon?

Write the $IUPAC$ names of the products obtained by the addition reaction of $HBr$ to $hex-1-ene$:
$(i)$ in the absence of peroxide and
$(ii)$ in the presence of peroxide.

Rank the following alkenes in order of decreasing heats of hydrogenation (largest first):
$1$. $1-$butene
$2$. $2-$methyl$-2-$butene
$3$. trans$-2-$butene
$4$. cis$-2-$butene

The volume of dihydrogen required for complete hydrogenation of $0.5 \ dm^{3}$ of ethene at $\text{S.T.P.}$ is (in $dm^{3}$)

Which of the following reactions is correct?

Vedclass Test Series

Exam Paper Generator

Online Exam Module