Orgo Destroyer #44.
Started by ddsjc2014
Well since the question says SN1 (2 steps first form carbocation then attack) just think if the Cl (or I for a) leaves which will be left with the most sable carbocation. Each one is drawn out in the answer key:
a) only secondary its not bad
b)wont happen
c)this one might be tricky. It looks nice because has 2 double bonds that should be able to help out with resonance but you cant forget about aromaticity. By creating that vacant orbital we now created an antiaromatic species. SO lets stay away from that answer choice.
d) its not bad secondary and doubly allylic
e)Best has a lot of resonance and by creating this vacant orbital you now have an aromatic species
a) only secondary its not bad
b)wont happen
c)this one might be tricky. It looks nice because has 2 double bonds that should be able to help out with resonance but you cant forget about aromaticity. By creating that vacant orbital we now created an antiaromatic species. SO lets stay away from that answer choice.
d) its not bad secondary and doubly allylic
e)Best has a lot of resonance and by creating this vacant orbital you now have an aromatic species
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I don't know the reason but i just know you just cannot have + charge in B..
but for E, by loosing Cl, it becomes aromatic which is very stable.
and Antiaromatic is 4n. You know 4n+2 makes aromatic? but if you have just 4n it is anti aromatic.
hope it helps./.
thanks for the explanation, helped me understand
but according to that, shouldnt D be anti-aromatic as well? In the solutions it says C is anti-aromatic but for D it says "fair" even though it is also just 4n...hope that makes sense, and appreciate the help!
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211183
there are three terms:
aromatic, anti aromatic, and non aromatic. I used to get the latter two mixed up as well.
aromatic is if it follow ALL the aromaticity rules
planar, conjugated system, ring, and sp2 AND is 4n+2 (you knew that)
if it FOLLOWS ALL of those..... BUT is 4n = antiaromatic
if it violates any one of those = nonaromatic
so if its not planar, not conjugated, not a ring, or has anything but sp2 carbons...
I forget which rings are nonplanar.... there are some higher #carbon ones that are and aren't. I don't know if they'd test those exceptions though.
Sorry if you knew that already- just trying to help!
aromatic, anti aromatic, and non aromatic. I used to get the latter two mixed up as well.
aromatic is if it follow ALL the aromaticity rules
planar, conjugated system, ring, and sp2 AND is 4n+2 (you knew that)
if it FOLLOWS ALL of those..... BUT is 4n = antiaromatic
if it violates any one of those = nonaromatic
so if its not planar, not conjugated, not a ring, or has anything but sp2 carbons...
I forget which rings are nonplanar.... there are some higher #carbon ones that are and aren't. I don't know if they'd test those exceptions though.
Sorry if you knew that already- just trying to help!
2
211183
Mine is Tuesday. I'm the same... still reviewing though...but at this point everything I review feels like a movie i've watched 10 times adn I can recite all the words.
I think it might be smart to do some QR practice and RC .... GOD I HATE TRIG! I don't think I will ever understand it.
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