Download Markovnikov`s Rule

Markovnikov's Rule
Alkene and Alkyne Rxns
SCH 3U0/4C0
Halogens Again
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Why would alkenes and alkynes undergo
halogenation reactions?
This time, we'll use halogen hydrides (HCl, HBr)
instead of Cl2 and Br2.
Why? Less waste. You'll see.
Double Trouble
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What's the rxn of ethene and hydrogen bromide
get you?
How about hydrogen chloride and
cyclohexene?
What about these four rxns?
The solution?
Explain how these products form if we haven't already.
And explain why I said there's “less waste.”
How About
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Ethene and hydronium?
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Hydrochloric acid and 2-hexene?
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Hydrogen chloride and 2-methyl-2-butene?
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Hydrogen bromide and 1-butene?
What's the rule?
Markovnikov's Rule
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When a Brønsted acid, HX, adds to an
unsymmetrically substituted double bond, the
acidic hydrogen of the acid bonds to that
carbon of the double bond that has the greater
number of hydrogen atoms already attached to
it.
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The H-rich get H-richer.
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Them that has the Hs gits the H.
Now
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Explain why the H-rich get H-richer (them that
has the Hs gits the H).
Hint: it might be easier if you ignore the Hs.
Then again, it might not.
What's the Cl doing here? Why?
Vladimir in Action
Predict the products.
Vladimir in Repose
Alkynes
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Now we open things up – alkane-type
halogenation is allowed.
What happens when you react bromine with 1penten-4-yne?
Why isn't it 4-penten-1-yne?
Multiple Markovnikov
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Butyne and HCl?
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2-butyne and HBr?
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Butyne and Br2?
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Ethyne and I2?
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What about if the above have halogens/halogen
hydrides in excess?
Useful Markovnikov
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What's the product
when ethyne reacts
with:
 HCl?
vinyl chloride
 Ethanoic
acid?
vinyl acetate
 Cyanic
acid?
acrylonitrile
Some common PVC products.
Monomers and Polymers
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Polymers are linked repetitions of monomers.
Polyvinyl alcohol: linked vinyl alcohols
(ethanols).
Polyethylene: linked ethylenes (ethenes).
Biological examples: DNA, proteins,
polysaccharides (like cellulose), ...
Making Polymers
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Let's make a couple polymers (small-scale, of
course): PVA/borate and Latex/borate.
Safety precautions and disposal instructions!
Liquid latex and borate.
Polyvinyl alcohol and borate linking into a web-like structure.
Oxidation
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Air is 21% oxygen.
Many chemicals have oxygen as a structural
component.
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Oxygen is electronegative.
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So pretty well everything will oxidize.
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Oxidation in organic chemistry: R+[O] →
products.
Oxidation, Organic Style
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What will simple
(mono) alkynes
oxidize to?
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What about alkenes?
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Alkanes?
Some hints.