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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How Concepts Build Up In Org 1 (“The Pyramid”)

September 5, 2014

I LOVE making maps. Whenever I played adventure games as a kid (or, let’s face it, as an adult) I often made meticulous maps of how each area led to the next. Any time I really want to understand something, I have to write everything out and make a map to connect things together – usually [...]

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Bredt’s Rule (And Summary of Cycloalkanes)

Bredt’s Rule (And Summary of Cycloalkanes)

September 2, 2014

At the beginning of this series I said that the fact that carbon forms rings leads to all kinds of interesting consequences that follow logically from the rules of structure and bonding in organic chemistry, but nevertheless would have been hard to predict from first principles. Among them, we’ve seen that: 3 and 4 membered rings have significant ring [...]

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How Helena Aced Organic Chemistry

How Helena Aced Organic Chemistry

August 28, 2014

How Helena Got 93 In Organic Chemistry An Australian reader, Helena, recently wrote to say she’d earned a 93 in her organic chemistry class as part of her course requirements as a biology major.  Here’s how she described her background: I’m a “mature age” student. The last time I studied chemistry was in high school twenty [...]

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Maybe they should call them, “Formal Wins” ?

Maybe they should call them, “Formal Wins” ?

August 15, 2014

In April of this year, Braves reliever Luis Avilan came in with a 5-1 lead in the 8th inning. Eight batters later, he’d given up five runs, blowing the lead. Thankfully for him, the Braves came back in the top of the 9th and reliever David Carpenter nailed down the save. The result: Avilan got [...]

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Bridged Bicyclic Rings (And How To Name Them)

August 14, 2014

In the last post we started our discussion of structures with more than one ring, using decalin as our key example. We saw how much the stereochemistry at the ring junction can affect the overall shape of the molecule, as well as its stability. What we didn’t talk about is that the ring junction of decalin [...]

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Fused Rings

August 5, 2014

At the beginning of this series I said that the fact that carbon can form rings leads to all kinds of interesting consequences. We’re going to see many examples of that in our post today! So far, we’ve only talked about cyclic molecules containing one ring. But, of course, molecules with multiple rings are very common [...]

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Which Cyclohexane Chair Is Of Lower Energy?

July 23, 2014

In the last post, we introduced A values and said they were a useful tool for determining which groups are “bulkiest” on a cyclohexane ring. The greater the A-value (bulk), the more favoured the equatorial conformer will be (versus axial). We saw that hydroxyl groups (OH) have a relatively low A-value (0.87), methyl groups are [...]

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Substituted Cyclohexanes: “A Values”

July 1, 2014

In the last post we saw that adding a methyl group to cyclohexane results in two chair conformers that are unequal in energy. We saw that the conformer where the methyl group was equatorial is the most stable, since it avoids destabilizing diaxial interactions (technically, gauche interactions) that are present in the conformer when the methyl group is axial. We also said [...]

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