Ketones

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 significant differences in chemical behavior. Previously, we saw that the sp hybridization of alkynes leads to increased acidity, and the [...]

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The Malonic Ester Synthesis

August 14, 2012

Apropos of nothing, here’s a post about a series of reactions that is a common source of student difficulties. It’s called the malonic ester synthesis, and it’s an interesting way of making substituted carboxylic acids. There’s an essentially identical process called the acetoacetic ester synthesis and it makes substituted ketones; the only difference between the two processes is [...]

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Reaction Friday: Keto-Enol Tautomerism

Reaction Friday: Keto-Enol Tautomerism

April 27, 2012

Today’s Reaction Friday is all about keto-enol tautomersm, the chemistry equivalent of Jekyll and Hyde. Included: Tautomers are constitutional isomers (not resonance forms) The same factors which stabilize alkenes stabilize the enol form How to draw the mechanism for tautomerism (and how NOT to draw it!) Related Posts:Reaction Friday: Formation of Acetals from KetonesAnother awesome [...]

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Weird Nomenclature In Carbonyl Chemistry

March 26, 2012

Making it through the chemistry of carbonyl derivatives (ketones, aldehydes, carboxylic acids, esters, and more) there are at least two “weird” nomenclature issues that repeatedly come up to baffle students: Greek letters, and “1,2-” or “1,4-” addition reactions.  In this post I’ll try to address them both.  1. Greek letters The functional group C=O is [...]

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Reaction Friday: Formation of Acetals from Ketones

Reaction Friday: Formation of Acetals from Ketones

February 24, 2012

Today’s video is about the formation of acetals from aldehydes and ketones, an important method for the protection of the carbonyl group. One thing I forgot to mention in the video is that the reaction is an equilibrium – choosing alcohol as the solvent ensures that the equilibrium will be driven towards formation of the [...]

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Reaction Friday: Addition of Grignard Reagents to Ketones

Reaction Friday: Addition of Grignard Reagents to Ketones

February 18, 2012

Grignard reagents are very useful carbon-based nucleophiles and will readily form carbon-carbon bonds with carbonyl compounds. Here the reaction of Grignard reagents with ketones is described, along with several examples and a detailed mechanism. Have a great weekend! Related Posts:Reaction Friday: Formation of Acetals from KetonesOn Acetals and HemiacetalsCarbonyl Mechanisms: Neutral Nucleophiles, Part 1Breaking Down Carbonyl [...]

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Reagent Friday: Zinc Amalgam (Zn-Hg)

Reagent Friday: Zinc Amalgam (Zn-Hg)

December 9, 2011

In a blatant plug for the Reagent Guide and the Reagents App for iPhone, each Friday  I profile a different reagent that is commonly encountered in Org 1/ Org 2.  What it’s used for: For our purposes, zinc amalgam has one important use: in the Clemmensen reduction of ketones to alkanes. Similar to: The reagent has essentially the same [...]

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Reagent Friday: Grignard Reagents

Reagent Friday: Grignard Reagents

October 14, 2011

In a blatant plug for the Reagent Guide and the Reagents App for iPhone, each Friday  I profile a different reagent that is commonly encountered in Org 1/ Org 2.  NOTE - I said that the Reagents app wouldn’t be free forever. Today’s the last day to pick up the Reagents app for free from the App Store! Get it [...]

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Reagent Friday: Hydrazine (NH2NH2)

Reagent Friday: Hydrazine (NH2NH2)

September 24, 2011

In a blatant plug for the Reagent Guide and the Reagents App for iPhone, each Friday  I profile a different reagent that is commonly encountered in Org 1/ Org 2.  The first time I ever heard about hydrazine, it was from my instructor for 3rd year advanced organic chemistry, Walt Szarek.  “If ya ever work with this stuff”, he [...]

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Reagent Friday: Ozone (O3)

Reagent Friday: Ozone (O3)

September 16, 2011

In a blatant plug for the Reagent Guide and the Reagents App for iPhone, each Friday  I profile a different reagent that is commonly encountered in Org 1/ Org 2.  Ozone is a molecule that most people are familiar with hearing about, either because it is missing (in the high atmosphere, where it absorbs UV radiation) or because [...]

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