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The SN1, E1, and Alkene Addition Reactions All Pass Through A Carbocation Intermediate

The SN1, E1, and Alkene Addition Reactions All Pass Through A Carbocation Intermediate

April 21, 2015

Was going to include this in my last post but it was getting too big. Note how the SN1, E1, and alkene addition reactions all pass through a carbocation intermediate. Here’s how they’re related. Starting with an alkene, adding strong acid gets us to a carbocation (A–>B). If the counterion to that acid is a […]

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In Speech, Obama Expresses Concern Over Growing Electron Inequality

In Speech, Obama Expresses Concern Over Growing Electron Inequality

April 1, 2015

WASHINGTON – In a speech at a black-tie meeting of the Periodic Table of the Elements last night, President Obama called on all atoms to share their electrons more equally. “Electron inequality represents the biggest problem that atoms face today. Disturbingly, chemistry has increasingly become divided into two groups: the electron “haves” and the electron “have-nots”. “Folks with the […]

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Weirdest spam comment I’ve had in awhile

Weirdest spam comment I’ve had in awhile

March 23, 2015

In the “WTF” category…   Author : Dr abdoul E-mail : cleaninglabyahoocom URL : http://www.cleaninglab.ga Comment: WELCOME TO CLEANINGLAB LABORATORIES (PTY) LTD. WE PROVIDE SSD SOLUTION CHEMICAL FOR CLEANING BLACK MONEY HI,THIS IS JUST TO INFORM YOU THAT OUR COMPANY CAN CLEAN OUT BLACK MONEY CALLED ANTI-BREEZE (STAINED MONEY) BANK NOTES SO PLEASE IF YOU […]

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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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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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Cycloalkanes – Ring Strain In Cyclopropane And Cyclobutane

April 3, 2014

In the last post we saw that cyclopropane and cyclobutane have an unusually high “ring strain” of 27 kcal/mol and 26 kcal/mol respectively.  We determined this by comparing heats of combustion from rings of various sizes, and saw that the ΔHcombustion per CH2 was essentially constant as ring sizes went above 12. Based on these […]

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Cycloalkanes – How To Calculate Ring Strain

March 24, 2014

In the last post we learned about one consequence of the fact that carbon can form rings – that we can form stereoisomers (cis / trans).  This post attempts to explain another very interesting consequence of ring formation. This whole post is about strain.  It all starts with this: it turns out you can learn […]

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Success Stories: How Zach Aced Organic Chemistry 1

Success Stories: How Zach Aced Organic Chemistry 1

January 16, 2014

With the first semester over, I recently asked my readers if they could share their stories of how they succeeded [or even failed in] organic chemistry. In the first of a series of posts, I’ll share the response from Zach, who reports earning an A in organic chemistry 1 at a prestigious Ivy League university […]

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Synthesis (2) – Reactions of Alkanes

Synthesis (2) – Reactions of Alkanes

December 19, 2013

In this post we’re going to begin building our reaction map, starting with the simplest organic compounds of all: alkanes.*We’ve only learned one synthetically important class of alkane reaction: free-radical halogenation. [Combustion is also technically a reaction of alkanes, but producing CO2 and H2O from organic starting materials is not very useful from a synthetic […]

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