Alcohols

Williamson Ether Synthesis: Planning

October 30, 2014

In the last post we introduced the Williamson ether synthesis,  one of the most straightforward ways we know of to make an ether. If you’ve been in the trenches long enough, you would have also noticed that it’s actually nothing that new –  the Williamson is just “rebranding” of a reaction we’ve seen before,  the SN2 [...]

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The Williamson Ether Synthesis

October 24, 2014

In the last post, we discussed the acid-base properties of alcohols. Two posts ago, we said that acid-base reactions are often used to “set up” substitution and elimination reactions of alcohols.  In this post, we’ll talk about what is probably the best example of this last point –  the Williamson Ether Synthesis. The Williamson Ether [...]

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Alcohols (3) – Acidity and Basicity

October 17, 2014

In the last post we said that one of the keys to the reactions of alcohols as we go forward is that the conjugate acid is a better leaving group and the conjugate base is a better nucleophile. We might have gotten a little ahead of ourselves broaching that topic, because we haven’t yet really revisited some [...]

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How To Make Alcohols More Reactive

How To Make Alcohols More Reactive

October 6, 2014

In the last post we explored some of the properties and nomenclature of alcohols. We said that alcohols tend to have high boiling points due to hydrogen bonding, and that  we commonly divide alcohols into the categories  “primary”, “secondary”,  and “tertiary” (with a nod to the unique, “methanol”) according to how many carbons are attached to the C [...]

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Alcohols (1) – Nomenclature and Properties

September 17, 2014

In this next series of posts we are going to discuss the reactions of alcohols. As a functional group, alcohols are introduced fairly early in organic chemistry. Their reactions, however, are usually not covered until near the end of Org 1 – at least after subjects like substitution and elimination reactions have been explored. That’s [...]

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How Concepts Build Up In Org 2

September 9, 2014

OK. Having looked at the Org 1 Concept Map, let’s ask the next logical question: what does a typical Org 2 course look like? One general observation: the way functional groups are covered in your typical two-semester organic chemistry course generally follows the oxidation ladder. Look at the progression:  alkanes (low oxidation state) first, then [...]

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SOCl2 and the SNi Mechanism

SOCl2 and the SNi Mechanism

February 10, 2014

Some time ago I published this post on Reagent Friday discussing the mechanism of SOCl2 converting secondary alcohols to alkyl chlorides with secondary  through an SN2 pathway: About six months ago this post arrived in the comments:  Slapdown! First of all, Rico is correct that the mechanism showing inversion with SOCl2 is not what happens experimentally. [...]

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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 Pathway In the Carbocation Pathway, the alkene acts as a nucleophile and attacks an electrophile, resulting in the formation of [...]

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Hydroboration of Alkenes

March 22, 2013

So far in this series on alkenes, we’ve gone through two families of mechanism pathways. In the carbocation pathway, we saw reactions that proceed with “Markovnikov” regioselectivity, a mixture of “syn” and “anti” stereochemistry, and can be accompanied by rearrangements.  In the 3 membered ring pathway, the regiochemistry is also “Markovnikov”, the stereochemistry is trans [...]

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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 for this reaction. Namely, the reaction proceeds with anti addition of substituents across the alkene, and (where relevant) the reaction proceeds with “Markovnikov“ [...]

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