Understanding the Impact of Strong Deactivating Groups on Elimination Reactions

[mystic-]

hey i wanted help on understanding a particular reaction
we have a compound
1(4-Nitrophenyl)-1-phenylpropan-2-ol and its reaction with concentrated sulphuric acid at the suitable temperature.
Actually our teacher said that it would form 1(4-Nitrophenyl)-1-phenylprop-1-ene after the elimination reaction but i was wondering that since NO2 is a strong deactivating -R group so it will not let the carbocation get stabilised at that position.
Am i thinking right that one of the resonating structures of the product so formed would lead to great destabilisation and increase in total energy content?
this is contradictory as this would give the compound with formula 3(4-Nitrophenyl)-3-phenylprop-1-ene
Could anybody give me the explanation for the product?

Thanks anyway

 

[siddharth]

mystic,

• The resonance stability increases with the increased number of contributing structures
• Whether a single hypothetical contributing structure will contribute significantly to resonance will depend on it's relative stability.

So, I think that while the N02 group will not stabilise the carbocation at that position, the other resonance structures (due to the phenyl group) will indeed stabilise the carbocation and thus form 1(4-Nitrophenyl)-1-phenylpropan-2-ol.

 

[mystic-]

yes i know that the phenyl does contribute to the stability with its resonating structures but isn't there a great rise in the energy of the compound and instability if there is any resonating structure which is destabilising and in this case it is a Strong -R group ( NO2)
anybody has any references to any sites which tells how resonance energy varies with such factors? i ll be grateful if somebody could provide me such a link