Final Flashcards
In the H NMR which solvent absorbs at 1.6?
Water
In the H NMR which solvent absorbs at 0 ?
TMS
Where does DMSO absorb on the H NMR spectrum?
2.5
Where does CDCl3/CHCl3 absorb on H NMR?
7.3 (usually gives a nifty looking triplet)
Where is a typical IR stretch found for C-O?
1100-1300
Where is a typical IR stretch found for sp3 C-H’s?
To the right of 3000
Where is a typical IR stretch found for aromatic C=C?
1450-1500
Where is a typical IR stretch found for C=C (not aromatic) ?
1650
True/False: Axial hydrogens are more shielded
True
How can you recognize an N-H peak in IR?
Look for the two short, but steep “hills” around 3300-3600
Where would you find a C=C stretch?
1600-1700
What is the formula for double bond equivalents (DBE)?
DBE=[(2*C+2)-H-X+N]/2
Where are the two C-C Nujol peaks in IR?
1456 and 1376
When would you use organocuprate reagents over Grignard reagents?
To form a ketone from a Carboxylic acid a less reactive reagent (like organocuprate) is needed
What is carboxylation?
When a Grignard reagent reacts with CO2 to form a Carboxylic acid with one more carbon than the Grignard had
What organometallic reagent(s) react with alpha, beta ketones to form the 1,2 product?
Organolithium and Grignard
What organometallic reagent(s) react with alpha, beta ketones to form the 1,4 product?
Organocuprate
Where does a Grignard reagent add carbons?
The carbonyl carbon
Where does a organocuprate reagent add carbons?
To the beta carbon
Where does a organolithium reagent add carbons?
The carbonyl carbon
Give an example of a typical protecting group?
TBDMS
Give an example of a typical deprotecting reagent?
Tetrabutylammonium fluoride
Which organometallic reagent requires two R-groups attached to it?
Organocuprates
How can you convert an acid chloride or an ester to an aldehyde?
Use bulky LAH (LiAlH[OC(CH3)3]3), or DIBAL-H
