Organic Chemistry 2

An Exercise In Mind Reading?

April 8, 2013

The other day while going through Claisen condensations with a student, we came upon this pretty typical problem: The student duly deprotonated the alpha carbon of the ester to give the enolate, but stopped there. “Since there’s just one molecule of ester, I’m not sure what it’s supposed to do next.” I explained that it’s [...]

Tagged as: claisen, dieckmann, enolates, esters, medschool

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Introducing the Reaction Guide

Introducing the Reaction Guide

October 17, 2012

My main goal at Master Organic Chemistry has always been to provide students with useful resources that they can’t easily find anywhere else. About six months after I started tutoring organic chemistry, I realized that a lot of students had trouble keeping track of all the reagents in organic chemistry, and were looking for a [...]

Tagged as: Reaction Friday, reaction guide, reactions

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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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What does 4n+2 mean?

What does 4n+2 mean?

June 29, 2012

The other night a student came to me with a question about aromaticity. “There’s one thing I don’t get”, she said. “They say a molecule has to have 4n+2 electrons. How do you find n?” Teachable moment! “n” is not a characteristic of the molecule! Let me explain. In order for a molecule to be aromatic, it [...]

Tagged as: 4n+2, aromaticity, benzene, huckel's rule, pyridine

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Announcing Daily Organic Chemistry Tips By Email

May 24, 2012

99% of what I do at MOC is given away for free. But every once in awhile I try to produce paid products and services that serve a pressing need for students of organic chemistry that can’t be found anywhere else. One example of this is the Reagent Guide. Today I’m excited to announce the [...]

Tagged as: organic chemistry study tips, orgo tips, shortcuts, tutoring

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Acid Base Reactions Are Fast

May 21, 2012

Common dilemma in organic chemistry as you move through the latter parts of Org 1 and then into Org 2: When more than one reaction is possible, how do you know which one will happen? In a steel cage match between an acid base reaction and other types of reactions, which wins? Here’s a good [...]

Tagged as: acidity, basicity, conjugate acid, conjugate base, nucleophile, nucleophilicity, pka, trick questions

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A Handy Rule of Thumb for Acid-Base Reactions

May 17, 2012

Last time I talked about pKa and how it’s the closest thing we have to a universal measurement of  the strengths of all kinds of different acids and bases.  I also referred to a post on how to use a pKa table (key lesson: stronger acid plus stronger base gives weaker acid and weaker base). [...]

Tagged as: acids, bases, conjugate acid, conjugate base, equilibrium, pka

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Organic Chemistry Study Tips: Reaction Maps

Organic Chemistry Study Tips: Reaction Maps

May 7, 2012

This time of year one of the most common problems students come to me with is how to do synthesis problems. Like this:  There’s a lot of different ways to go about learning how to do synthesis – and I’ll have a lot more to say about that in future posts – but today’s post [...]

Tagged as: grignard, ketones, reactions, retrosynthesis, secondary alcohols, study tips, synthesis

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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 [...]

Tagged as: enols, ketones, Reaction Friday, tautomerism, video

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Polar Protic? Polar Aprotic? Nonpolar? All About Solvents

April 27, 2012

A lot of students I talk to have questions about solvents, so I’ve decided to put together a reference post on them. Solvents can cause considerable confusion in reactions, because they’re listed along with the reagents of a reaction but often don’t actually participate in the reaction itself. And to be honest, a lot of [...]

Tagged as: dmf, dmso, hydrogen bonding, mecn, nucleophiles, polar aprotic, polar protic, solvents, thf

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