The New Clayden pp. 382 – 426

Very few comments to make on these 44 pages.  The text is clear as a bell, and very standard stuff is introduced.

 The illustrations in the book that I comment on can be reached on the web by substituting the page number I give for xx in the following

www.chemtube3d.com/clayden/xx

p. 395 — The ability to rotate the 2 Bromo butane molecule in space and watch E2 elimination from all angles is incredible and allows you to understand what is going on.  It is rather humbling to look at the reaction in ‘spacefill’ mode showing the electron clouds, rather than the more schematic ball and stick mode.  It’s much harder to ‘see’ what is going on, yet molecules are performing this dance every femtosecond.

p. 396 — ditto for the more complicated stereospecific E2 mechanism of 1 Bromo, 1 phenyl 2 phenyl propane.

P. 397 — If you step through the conformations of diastereomers one frame at a time and rotate the molecule in space, you can actually see what the half chair conformation of cyclohexane actually looks like.  You can get 4 consecutive carbons in one plane, with the remaining 2 above and below the plane they define.  Hallelujah ! 

p. 411 — Nice description of the battle between inductive and conjugation effects on carbonyl stretching frequency in the infrared.  This sort of ability to balance two conflicting trends is identical to the type of reasoning a physician must apply to a patient. Exactly why future docs should have the mental capacity to take and pass organic chemistry.  Side effects must always be balanced against benefit for any drug or surgical procedure, usually without a lot of the data you need to do it right.  

p. 412 — Notice the distinction between the frequency of absorption of the carbonyl group, and the amount of light actually absorbed (the intensity).  The authors did miss a bet in explaining why the intensity of the carbonyl increases with conjugation (the dipole moment of one of the resonance forms is greater). 

p. 415 — A picture of the actual triplet triplet would be nice.

p. 416 — I sometimes forget that 1 part per million on a 250 MHZ machine is 250 Hertz (but I shouldn’t).  You certainly would miss > 2 ppm coupling in the hydrogen spectrum which has a range of only 10 ppm. 
Advertisements
Post a comment or leave a trackback: Trackback URL.

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s

%d bloggers like this: