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When pent-2-ene reacts with HBr. what are the products formed and what is the major product?
I know the products formed are 3-bromopentane and 2-bromopentane but which one is major product?? give explanation please
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106but why not hyperconjugation?
hyperconjugation dominates inductive effect (it doesnt if the substituent is highly electronegative which in case of Bromine is not).
1but in 3-blahblah... there are four hyperconju!
but in 2nd position, there are only 3.
106but i thought hyperconjugation dominates inductive effect (it doesnt if the substituent is highly electronegative which in case of Bromine is not)...... please help
1I FEEL U SHUD USE SYTZEFF RULE
THE I WITH LESSER NO. OF H WITH C WILL B MAJOR
I THINK SO
1in 3-b we hav 4 hyperconjugations + higher inductive + symmetry
thats y it shud be the major one
also 2-bromo has 5 hyperconjugations but 4 & 5 is not much of a difference with hyperconjugation
1during electrophilic rexn and unsymmetrical alkene electrophile attacks at less hindered carbon atom.
3shud be inductive effect ive seen the mechanism in mah fiitjee material...........
it says 3- bromopentane is major product!!!!!!
1this is reaction in which a carbocation intermediate is formed not a transition state....that is why it shud be 2-bro... not 3-bro...
106yes that was my reason for 3-brom.... now question is which one will dominate??? i think hyperconjugation
3SEE IN PRESENCE OF AN ATTACING AGENT THE Î ELECTRONS CAN SHIFT TO C2 OR C3 .....
but if u see theres also a role played by inductive effect
the c5 and c4 release electron towards the c3 carban as compaired to only c1 relaeasing electron towards the c2 carbon.......
hence the electron shifts towards the c2 carbon...................
thus the c3 carbon is now positive and the negatively charged bromine attaches there!!!!!!!!
thus the 3- bromopentane is major product!!!![1]
106my explanation for 2-brom...was exactly that but i also hav a reason for 3-brom.... lets wait for iitimcomn's answer then ill giv my reason... it has to do with inductive effect...
106explain watever is answer plz explain..... i hav 1 explanation each for the products as to y either can be major..... but i want opinions of u guyz as well
1i feel 2-bro.... will be the major product as the carbocation in this is more stable as it has 5 hyperconjugable pairs rather thann 4 in the later....so ans shud be 2-bro....