Nomenclature

Homotopic, Enantiotopic, Diastereotopic

April 17, 2012

When you have two hydrogens attached to a single carbon, they can have three different types of relationships. We call them “homotopic”, “enantiotopic”, and “diastereotopic”. First of all, when is this important?  Certain reactions directly replace hydrogens with other atoms. For example, free radical chlorination replaces C-H bonds with C-Cl bonds. So understanding these principles [...]

Tagged as: diastereotopic, enantiotopic, homotopic, NMR

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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 [...]

Tagged as: 1, 2, 4-addition, aldehydes, alkenes, alpha, dienes, ketones, nomenclature

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Don’t Be Futyl, Learn The Butyls

Don’t Be Futyl, Learn The Butyls

November 10, 2011

Nomenclature: what a headache. We’ve got all these accumulated years of jargon regarding chemical structures, and unless you learn the lingo, it can be confusing to follow what’s going on. Case in point: butyl. There are FOUR different types of “butyls”, and they all have their own name. In addition they each have a common [...]

Tagged as: alkanes, butyl, conventions, isomers, n-butyl, nomenclature, s-butyl, t-butyl

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Oxidation and Reduction in Organic Chemistry

August 1, 2011

Iron smelting!  Photo credit: http://sclowcountryoutdoors.blogspot.com/2011/02/iron-smelting-at-acba.html In the beginning, the term actually made sense. When the alchemists and medieval metallurgists started doing experiments to quantify exactly how much iron, say was formed from the smelting of a given amount of iron ore, they found that the weight of the solid iron was always less than that of [...]

Tagged as: hydrogenation, oxidation, reduction, weird names

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Condensed Formulas: Deciphering What the Brackets Mean

June 20, 2011

Recall that there are at least 4 major ways of representing molecules that you’re introduced to in the first week of ochem. The highest level of detail is the Lewis dot structure, which shows where all the electrons are with dots. The second highest level of detail is the structural formula, which replaces those dots [...]

Tagged as: alkanes, brackets, condensed formulas, isomers, nomenclature

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Table of Functional Group Priorities for Nomenclature

February 14, 2011

Because I figured I should have it on this site somewhere – although this covers most of the functional groups you’ll meet in Org1/Org2, if you run into a thioketone or some other bizarre entity, you’ll probably want to see Reusch or Wikipedia.    Here are some examples of applying the order of functional group [...]

Tagged as: alcohols, esters, functional groups, nomenclature, priorities

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The 8 Types of Arrows In Organic Chemistry, Explained

February 9, 2011

To my knowledge there are 8 different types of arrows you meet in organic chemistry. Here’s a little guide to them. 1. The forward arrow, otherwise known as the “reaction arrow”. The purpose of this arrow is to show action. Now, “BH3, then NaOH/H2O2″ might not exactly seem like  your idea of “action”, but put [...]

Tagged as: arrows, conventions, curved arrows, equilibrium, lists, resonance, summaries, synthesis

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Org 1 Review Quizzes

January 7, 2011

This past semester after every tutorial session I would send an email to my student with a list of topics that we discussed, and then a list of questions intended to stimulate thinking about the key concepts we talked about. I still do this: I think it’s helpful for both me and the student to [...]

Tagged as: help, org 1, problems, quizzes, resources, review

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Summary Sheet – Alkane Nomenclature

October 30, 2010

Part of the problem with nomenclature is that the trivial names can cause a lot of confusion. By themselves, the IUPAC names are at least logical, if sometimes unwieldy – it might be a good plan to just stick to one system as much as possible. I thought it would be worthwhile to put all [...]

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The Many, Many Ways of Drawing Butane

October 15, 2010

One of the skills you have to develop early in Org 1 is to learn the different conventions for drawing molecules. Let’s use butane as an example. Butane is pretty boring molecule, frankly. It’s four carbons in a row. Not much more to it than that. However, even a simple molecule like butane can be [...]

Tagged as: abbreviations, alkanes, bond rotations, conformations, dashes, drawing, hidden hydrogens, newman projections, nomenclature, wedges

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