conformations

s-cis and s-trans

s-cis and s-trans

May 12, 2017

s-cis and s-trans. What does those terms mean? Recall cis and trans. The reason Aldrich Chemical Co. can sell 99% cis-2-butene and 99% trans-2-butene in separate bottles is because of restricted rotation about the …

Read the full article →
Assigning R/S To Newman Projections (And Converting Newman To Line Diagrams)

Assigning R/S To Newman Projections (And Converting Newman To Line Diagrams)

February 1, 2017

This post was co-authored with Matt Pierce of Organic Chemistry Solutions.  Ask Matt about scheduling an online tutoring session here. In two recent posts we discussed how to assign (R/S) to configurations of chir…

Read the full article →
How To Do Bond Rotations

How To Do Bond Rotations

July 6, 2012

Bond rotation can be a tricky skill for first timers, and it’s a subject that doesn’t really lend itself to a text-laden blog post. You just have to “see it in action”. This video walks through…

Read the full article →
The Ups and Downs of Cyclohexanes

The Ups and Downs of Cyclohexanes

March 16, 2011

Drawing cyclohexane chair forms can be a tricky business. While it’s often intuitive to pick out which groups are up and down when they’re axial (i.e. pointing straight up or down), it’s tougher for …

Read the full article →
On Cats, Part 3: Newman Projections

On Cats, Part 3: Newman Projections

November 22, 2010

Do you know where the saying “there’s more than one way to skin a cat” comes from? Me neither. But I do know one thing: there is more than one way to draw cat conformations. Last time I introduced th…

Read the full article →
On Cats, Part 1: Conformations and Configurations

On Cats, Part 1: Conformations and Configurations

November 11, 2010

[NOTE: this has been amended to correct some confusion on my part on the difference between configurational and constitutional isocats. Thanks to Prof. Gary Weisman (UNH) for making me aware of the error] As I said ea…

Read the full article →
The Many, Many Ways of Drawing Butane

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 carbon…

Read the full article →