Organic Chemistry 1

Grignard Reactions And Synthesis (2)

Grignard Reactions And Synthesis (2)

January 19, 2016

Here’s the summary for today’s post on synthesis incorporating Grignard reagents and oxidants: Synthesis Using Grignard Reagents (Part 2) In the last post we saw how to approach some fairly straightforward synthesis problems using Grignard reagents. We learned how to think backwards from our final products (alcohols) to appropriate precursors for a Grignard reaction (aldehydes, […]

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Organometallics Are Strong Bases

Organometallics Are Strong Bases

November 13, 2015

Last post we talked about how to make certain organometallics, specifically Grignard and organolithium reagents. One thing we saw is that it’s useful to think of them as “carbanions”, that is, carbons bearing a negative charge. We’ve also seen that carbanions tend to be strong bases, as they are the conjugate bases of alkynes (pKa […]

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Synthesis of Grignard and Organolithium Reagents

Synthesis of Grignard and Organolithium Reagents

November 9, 2015

In the last post we introduced the concept of organometallic compounds – molecules where carbon is bound to a less electronegative atom such as Li, Mg, Cu, and many other metals. We said that carbon in these molecules tends to be electron-rich and thus have nucleophilic character, in contrast to functional groups such as alkyl […]

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What’s An Organometallic?

What’s An Organometallic?

October 28, 2015

Quick summary for today – the first in a new series on organometallic compounds: Previously on MOC we’ve discussed how important dipoles are in determining the reactivity of a molecule. Wait: dipoles, you might ask. How do we determine a dipole again?  Let’s start this series by making sure we’re clear on this, because it will be […]

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Thiols And Thioethers

Thiols And Thioethers

July 5, 2015

Here’s a summary of today’s post on thiols: Thiols and Thioethers One of the most powerful insights from learning the periodic table is the fact elements in the same period (column) have similar chemical properties. For instance Alkali metals (Li, Na, K…) all shed an electron relatively easily to form monovalent cations Halogens (F, Cl, Br) […]

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Protecting Groups For Alcohols

Protecting Groups For Alcohols

June 17, 2015

Summary for today’s post on Protecting Groups: When Alcohols Get In the Way As we’ve seen in previous posts in this series, alcohols are very versatile functional groups that participate in a variety of reactions. They can be deprotonated with base (making them good nucleophiles in substitution reactions), protonated (making them good leaving groups in […]

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Intramolecular Reactions of Alcohols and Ethers

Intramolecular Reactions of Alcohols and Ethers

June 12, 2015

“Intramolecular Reactions Make Me Crumple Into The Fetal Position Crying For My Mommy” Here’s a topic which doesnt really fit neatly in with what we’ve discussed before but it’s essential to any discussion of alcohols and ethers. Intramolecular reactions.  Here’s the executive summary: Intramolecular reactions [i.e. reactions where two functional groups in a molecule react […]

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PBr3 and SOCl2

PBr3 and SOCl2

March 20, 2015

Lately we’ve been talking a lot about converting alcohols to good leaving groups [halides] [tosylates and mesylates] You might think we’d be done already, but not yet! In today’s post we talk about a third important method for converting alcohols to good leaving groups – by using the reagents phosphorus tribromide (PBr3) and thionyl chloride […]

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Tosylates And Mesylates

Tosylates And Mesylates

March 10, 2015

Today we’re going to talk about a different way of making alcohols into good leaving groups – by turning them into tosylates and mesylates (“organosulfonates”). Here’s a brief summary of what we’ll cover here: Making Alcohols Into Good Leaving Groups, Part 2 We’ve seen that alcohols are poor substrates for substitution reactions. The main problem is that […]

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Making Alkyl Halides From Alcohols

Making Alkyl Halides From Alcohols

February 27, 2015

Making Alkyl Halides From Alcohols In today’s post we show that treating alcohols with HCl, HBr, or HI (which all fall under the catch-all term “HX” where X is a halide) results in the formation of alkyl halides. We’ve said many times in this series of posts that alcohols are poor substrates for SN1 and SN2 […]

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