stereoisomers

Cycloalkanes – Dashes And Wedges

Cycloalkanes – Dashes And WedgesMarch 20, 2014

In the last post, we mentioned that one of the consequences of the fact that carbon can form rings is that small rings (less than 8 carbons) are so rigid that they can’t be turned inside out [video]. One of the …

How To Do Bond Rotations

How To Do Bond RotationsJuly 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…

Introduction to Addition Reactions

Introduction to Addition ReactionsOctober 3, 2011

Following up on the 4 most important reactions you learn in Org 1, and the posts on acid-base and substitution reactions, here’s the third in the series: addition reactions. You’ll have to know line diagra…

On Cats, Part 6: Stereocenters

On Cats, Part 6: StereocentersDecember 15, 2010

Let’s recap what we’ve talked about so far. Sawhorse cat and Freaky Sawhorse cat are constitutional isocats. But Freaky Sawhorse Cat has a mirror image of himself crawling around somewhere – a cat t…

On Cats, Part 5: Enantiocats vs. Diastereocats

On Cats, Part 5: Enantiocats vs. DiastereocatsDecember 6, 2010

I was out for a walk the other day and I saw 3 of the weirdest/ugliest looking cats I’d ever seen.Even weirder than Freaky Sawhorse cat. Luckily I got pictures because nobody would believe me if I described them…

On Cats, Part 4: Enantiocats

On Cats, Part 4: EnantiocatsNovember 29, 2010

A few weeks ago we moved away from our old neighborhood where I first saw Sawhorse Cat. However a few days ago my friend Walter (who knows I like pictures of cats) told me he thought he saw him hanging around the old …

Selective vs. Specific

Selective vs. SpecificJuly 2, 2010

Many of the transformations you will encounter have the potential to create multiple products – isomers – from a single starting material. The reactions shown in the drawing, for instance (I’ve left …

Ephedrine and Pseudoephedrine

Ephedrine and PseudoephedrineMay 26, 2010

These molecules make the news quite a bit. Some questions to think about: What’s the (R),(S) designation for the stereocenters of ephedrine and pseudoephedrine, as drawn? What’s best way to describe the re…