Chemical Forums
Chemistry Forums for Students => Organic Chemistry Forum => Topic started by: zephy on November 10, 2004, 03:12:36 AM
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I'm having trouble memorizing all these mechanisms and reactions with alkanes, alkenes, and alkynes. Does anyone know an organized resource with a chart featuring the mechanisms/reactions with the exceptions, like, in an acidic environment, this happens, etc. I'm planning on making on myself, too, to see if the confusion will lessen, but I want to catch the smaller details in case I miss them.
Thanks.
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it will be so much easier to memorise if u understand the logic of the mechanism. in this way, if u miss out few details, you can still manage to work out the missing pieces.
eg. a delta positive carbon normally would attract nucleophiles. eg. SN1 mechanism.
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why don't you create your own chart so, it's easier for you to understand it
like what geodome said, understand the mechanisms themselves
and when you do you'll know when it would be in a basic or acidic environment
eg. the presence of a strong base forces dehydrohalogenation of alkyl halides to undergo E2 mechanism whether its primary, secondary, or tertiary
let me list some mechanisms for you though
a.SN1-SN2
b. free radical substitution
c. E1-E2 dehydration of alcohols
d. E1-E2 dehydrohalogenation of alykyl halides
e. electrophilic addition of hydrogen halides (markovnikov)
f. free radical addition of hrydrogen bromide to alkenes (anti-markovnikov)
g. sulfuric acid addition (markovnikov)
h. acid catalyzed hydration of alkenes (markovnikov)
i. hyroboration-oxidation of alkenes (anti-markovnikov)
j.hydrogenation of alkenes
k. addition of halogens forming vicinal dihalides
l. conversion of alkenes to vicinal halohydrin
m. epoxidation
n. ozonolysis of alkenes
good luck on your test if you have one
put it this way, I find Organic Chemistry to be hard too
i got a 36 in my ACT
all my grades so far in college are in the 100 percentile and over (some proffs don't curve)
but my organic is only at a 94 percent >:(
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Thanks for the list - I've been writing up the mechanisms and notes for each, so hopefully they'll be useful.
I'll probably have more questions later about particular reactions. :)
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I was wondering in which reactions is stereochemistry (is this the wrong term?) important, as in I would have to draw the dashes/wedges on the compound. Most of the reactions just have the bond-line drawings. The only few I see emphasized in my textbook are hydroboration, catalytic hydrogenation, halogen addition... Hmmm
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Stereochemistry is always relevant. Stereochemistry has the potential to change whenever a mechanism has a planar transition state.
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If you are looking for mind maps for organic chemistry, Chemistry by EN Ramsden is a good A level textbook to make reference to. It comes with plenty of mind map
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I agree with the mods, it's always important, but what is more important for now is you know/understand the reaction itself first
I'm thinking of buying "Organic Chemistry for Dummies" :)
that's if they have it lol
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I'm thinking of buying "Organic Chemistry for Dummies" :)
that's if they have it lol
Lol, that would be useful.
I have a question about Hofmann and Saytzeff rules - do they apply only to elimination reactions? I think eliminations are usually used to form an alkene from and alkane, right? It involves using bulky bases to form double bonds in certain positions when more than one is possible - so how does this occur, or why does using a bulky base cause a Hofmann elimination?
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Zaitsev's rulse pertains to regioselectivity or in other words, forming of the most substituted(stable) alkene
im not sure about the other one, maybe the mods can help you with that
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A very nice explanation of Hofmann's rule here:
http://www.organic-chemistry.org/frames.htm?http://www.organic-chemistry.org/namedreactions/hofmann's-rule.shtm