Thursday, August 30, 2007

ch. 9 homework NMR

Here is more homework for chapter 9. These problems include NMR.
27-29, 31, 33, 35, 37-41, 44

ch. 9 homework ms

Today we will begin talking about mass spectrometry (Ch 9). The homework for this is #'s 25, 26, and 40.

Tuesday, August 28, 2007

Spectroscopy

Today we will be moving along to talk about spectroscopy and will be covering IR, UV, and NMR along with mass spectrometry. Homework for the IR portion in Ch 2 is as follows: 38, 43-47.

Wednesday, August 22, 2007

CARBONYL REDUCTIONS


There really are only 2 issues to remember with carbonyl reductions and they are outlined in the 2 equations on this post. First, the negatively charged hydride source (LAH or NaBH4) transfers hydride (H-) to the carbonyl carbon to give an oxygen anion which becomes protonated upon workup (not shown).
The second thing to remember is that when esters or acids are reduced, 2 equivalents of hydride (remember that only LAH will reduce these) are transfered to the carbonyl. The reason for this is that the initial, tetrahedral intermediate, is unstable. This gives an aldehyde which goes on to react with LAH. Don't get caught up in what the aluminum or boron species looks like...just think of these as simple nucleophile-electrophile or acid, base couplings and remember that the proton on the alcohol that results from these comes from water.

Tuesday, August 21, 2007

Welcome

Class,
I will use this blogsite to post problems and answer questions. Chapter 12 homework: 11-26