1
yes no
·2009-10-14 23:45:24
ring expansion can occur
carbon in the cyclopropane has sp3 hybridisation(shld have 109.5 degree bond angle)..but actually it is only 60 degree. So ,to relieve angle strain,ring expands to form a 4 carbon ring ,cyclobutane(90 degree bond angle)!!
2)) tert butyl more stable because of 9 hypercojugative structure.An exception where hyperconjugation dominates over resonance stablisation.
9 hyperconjugation > resonance
13
Avik
·2009-10-15 01:28:13
Ring expansion wud occur as Cyclo Butane is stabler than a cyclo propane......
n fr the 2nd Hyperconj. is given preference over allylic Resonance.....
106
Asish Mahapatra
·2009-10-15 02:57:11
1. instead of ring expansion a viable option is there if u consider its hyperconjugative structure which is free of any sort of strain which was posted by mahato in one of my doubts
here's the link:
http://targetiit.com/iit-jee-forum/posts/complete-the-reactions-11185.html
2. tert butyl carbocation has 9 Hyper Hydrogens which overpowers the sole contribution of resonance in allylic as well as benzyllic carbocations
23
qwerty
·2009-10-15 06:52:29
So wat shud i deduce ...ring expansion occurs or not ?? to form a 90degree free of strain secondary C+ OR no ring expansion ???
11
Gone..
·2009-10-15 07:29:46
NO RING EXPANSION WONT OCCUR..
tHE reactant is more stable than even the following compunds...
&
this is because the positive charge is delocalized in the p-orbitals...draw the p-orbitals of the 4 carbons..ul c how.
11
Gone..
·2009-10-15 07:30:49
sorry for the space..dont know how to decrease it..
23
qwerty
·2009-10-15 09:56:14
kk tnx ..i expected dat answer....jus wanted to know the reason for it
39
Pritish Chakraborty
·2009-10-24 03:54:12
The cyclopropane ring is under high angle strain, packing those bonded electrons under 60° angles. Having an electron deficient adjacent carbon helps relieve some of the strain on the ring.
23
qwerty
·2009-10-24 10:56:33
"Having an electron deficient adjacent carbon helps relieve some of the strain on the ring."How???
abhi bataya hai to explain karna hi padega lolz [6]
39
Pritish Chakraborty
·2009-10-24 10:58:34
p orbital delocalisation? the carbocation craves electrons much like you crave pizza :P
23
qwerty
·2009-10-24 11:55:18
are u talking abt hyperconjugation ???? lolz aisa bol na ...itna complex me mat bata ....main tere jaisa organic ka master nahi hai ...lolz [3]