Final

Question 0

In the H NMR which solvent absorbs at 1.6?

Answer 0

Water

Question 1

In the H NMR which solvent absorbs at 0 ?

Answer 1

TMS

Question 2

Where does DMSO absorb on the H NMR spectrum?

Answer 2

2.5

Question 3

Where does CDCl3/CHCl3 absorb on H NMR?

Answer 3

7.3 (usually gives a nifty looking triplet)

Question 4

Where is a typical IR stretch found for C-O?

Answer 4

1100-1300

Question 5

Where is a typical IR stretch found for sp3 C-H’s?

Answer 5

To the right of 3000

Question 6

Where is a typical IR stretch found for aromatic C=C?

Answer 6

1450-1500

Question 7

Where is a typical IR stretch found for C=C (not aromatic) ?

Answer 7

1650

Question 8

True/False: Axial hydrogens are more shielded

Answer 8

True

Question 9

How can you recognize an N-H peak in IR?

Answer 9

Look for the two short, but steep “hills” around 3300-3600

Question 10

Where would you find a C=C stretch?

Answer 10

1600-1700

Question 11

What is the formula for double bond equivalents (DBE)?

Answer 11

DBE=[(2*C+2)-H-X+N]/2

Question 12

Where are the two C-C Nujol peaks in IR?

Answer 12

1456 and 1376

Question 13

When would you use organocuprate reagents over Grignard reagents?

Answer 13

To form a ketone from a Carboxylic acid a less reactive reagent (like organocuprate) is needed

Question 14

What is carboxylation?

Answer 14

When a Grignard reagent reacts with CO2 to form a Carboxylic acid with one more carbon than the Grignard had

Question 15

What organometallic reagent(s) react with alpha, beta ketones to form the 1,2 product?

Answer 15

Organolithium and Grignard

Question 16

What organometallic reagent(s) react with alpha, beta ketones to form the 1,4 product?

Answer 16

Organocuprate

Question 17

Where does a Grignard reagent add carbons?

Answer 17

The carbonyl carbon

Question 18

Where does a organocuprate reagent add carbons?

Answer 18

To the beta carbon

Question 19

Where does a organolithium reagent add carbons?

Answer 19

The carbonyl carbon

Question 20

Give an example of a typical protecting group?

Answer 20

TBDMS

Question 21

Give an example of a typical deprotecting reagent?

Answer 21

Tetrabutylammonium fluoride

Question 22

Which organometallic reagent requires two R-groups attached to it?

Answer 22

Organocuprates

Question 23

How can you convert an acid chloride or an ester to an aldehyde?

Answer 23

Use bulky LAH (LiAlH[OC(CH3)3]3), or DIBAL-H

Question 24

Where do nitro peaks show up in the IR?

Answer 24

Two peaks around 1350 and 1550

Question 25

What do anhydrides look like in the IR?

Answer 25

There are two carbonyl peaks

Question 26

What do esters look like in the IR?

Answer 26

Two peaks around 1250 and 1050

Question 27

Can you get a carbonyl at 1600?

Answer 27

Yes, because there could be resonance which weakens the bond, like for an amide or an ester

Question 28

What does a CNMR peak look like for a carbon bonded to nitrogen?

Answer 28

It is a small peak

Question 29

Where does a DMSO in water peak show up in the HNMR?

Answer 29

3.4

Question 30

How do you calculate Rf from a TLC plate?

Answer 30

Distance the sample traveled divided by the distance the solvent traveled
Helps you distinguish between two different molecules based on polarity

Question 31

Why did the reverse reaction not occur in the photoisomerization lab?

Answer 31

Because glass blocks UV light which is required for the reverse reaction