markovnikov

Opening of Epoxides With Acid

Opening of Epoxides With Acid

February 2, 2015

Here’s what we’re covering in this post. Opening Epoxides With Aqueous Acid In the last post, we saw some examples of how epoxides are considerably more reactive towards breakage than are ordinary ethers. …

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Alkyne Reaction Patterns – The Carbocation Pathway

Alkyne Reaction Patterns – The Carbocation Pathway

May 24, 2013

In the previous three posts on alkynes we’ve introduced some new reactions that are specific to alkynes (versus alkenes): deprotonation (and subsequent substitution), partial reduction to alkenes, and the format…

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Hydroboration and Oxymercuration of Alkynes

Hydroboration and Oxymercuration of Alkynes

May 14, 2013

Alkyne chemistry bears many resemblances to alkene chemistry, but in these first few posts on the subject, the purpose is to illustrate how one seemingly minor change – an extra π bond – can lead to sign…

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Summary: Alkene Reaction Pathways

Summary: Alkene Reaction Pathways

April 25, 2013

In this post we’ll do a final review of alkene addition reactions and sum up the three major pathways (and two minor classes of reactions worth paying attention to). Reaction Pathway #1 – The Carbocation P…

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A Fourth Alkene Addition Pattern – Free Radical Addition

A Fourth Alkene Addition Pattern – Free Radical Addition

April 12, 2013

I’ve written that there are three major alkene reactivity patterns [carbocation, three membered ring, and concerted], but there are two minor pathways as well. This post discusses one of them. As discussed previ…

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Alkene Addition Pattern #2: The “Three-Membered Ring” Pathway

Alkene Addition Pattern #2: The “Three-Membered Ring” Pathway

March 20, 2013

The “Three-Membered Ring” pathway In the last post we walked through a proposal for how the bromination of alkenes works and showed that it adequately explains many of the experimental observations made fo…

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Bromination of Alkenes: The Mechanism

Bromination of Alkenes: The Mechanism

March 15, 2013

In the last post of this series we showed how the mechanism for bromination of alkenes can’t possibly go through a carbocation intermediate. Why not? We have at least 3 good reasons: The two atoms that form new …

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Bromination of Alkenes – How Does It Work?

Bromination of Alkenes – How Does It Work?

March 6, 2013

In a previous post we went through the key reactions of the carbocation pathway. It’s a family of reactions which proceed through 1) attack of an alkene upon an acid, forming a free carbocation, and 2) attack of…

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Addition Pattern #1: The “Carbocation Pathway”

Addition Pattern #1: The “Carbocation Pathway”

February 22, 2013

MOC: What were some of your biggest roadblocks in learning organic chemistry? OCI: Not learning the patterns. I think I wasn’t told that there were patterns. -from this post A Key Pattern For Alkene Addition Rea…

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Markovnikov’s Rule (2) – Why It Works

Markovnikov’s Rule (2) – Why It Works

February 11, 2013

Understanding Why Markovnikov’s Rule Works Let’s assemble all the facts we know about the reactions of alkenes with an acid like HCl so far. Regiochemistry: as we saw in the last post, reactions of alkenes…

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