Part 8

Question 1

HCN + aldehydes or ketones –> ??

Answer 1

Aldehydes and ketones react with HCN to produce stable compounds called cyanohydrins. (CN and OH attached to same carbon group)

Question 2

Aldehyde + Aldehyde + base –> ??

e.g. two acetaldehyde molecules + base –> ??

Answer 2

Aldol Condensation reaction:

Aldehyde acts as both nucleophile and target. This will create an aldol = aldehyde + alchohol.

Product: a beta-hydroxyaldehyde

Question 3

Define spin splitting in HNMR?

Answer 3

If two magnetically different protons are within three bonds of each other a phenomenon known as coupling, or splitting occurs.

Question 4

Note on E2 reactions regarding base used

Answer 4

Bulkyness of base affects the hydrogen attacked on species. Will attack less substituted if base is bulky.

If base is not bulky, then it will attack most substituted.

Question 5

Concerted reaction

Answer 5

Chemical reaction in which all bond breaking and bond making occurs in a SINGLE step.

Question 6

Which of the following would be the best solvent for an SN2 reaction?

a. H2O
b. CH3OH
c. CH3SOCH3
d. heptane
e. tosylate

Answer 6

c. CH3SOCH3 (dimethyl sulfoxide) gives best results if a polar aprotic solvent is used.

a and b are wrong because these are both polar.
D is a heptane and is incorect because it is a nonpolar solvent.
c. tosylate is a good leaving group not a solvent.

Question 7

Combustion

Answer 7

Reaction of alkanes with molecular oxygen to form Carbon dioxide, water, and heat.

Question 8

CH3COOH + CH3MgBr –> ??

Answer 8

CH3COO-

Grignard reagents normally convert esters and ketones to alcohols.

Question 9

Williamson Ether Synthesis is an example of what type of reaction?

a. E2 or SN2
b. E2
c. SN2
d. E1 or SN1
e. two of the above

Answer 9

c. SN2

William Ether synthesis produces ethers from reaction of metal alkoxides with primary alkyl halides or tosylates. Via an SN2 reaction.

Question 10

RCOOH + NaOH –> ??

Answer 10

RCOO-Na+ (a soap) + H2O

Question 11

Peroxycarboxylic acids (mcpba or m-chloroperoxybenzoic acid)

Answer 11

Alkenes can be oxidized with mcpba. The products are formed are OXIRANES.

Question 12

True or false: Phenol can exist as a very temporary and less stable keto form via tautomerizing?

Answer 12

TRUE

Question 13

Ozonolysis

Answer 13

Reduction mechanism. Results in aldehydes or ketones depending on treatment.

Question 14

Alkyne + O3 –>

Answer 14

Alkynes can be oxidatively cleaved with ozone to make 2M COOH.

Question 15

Which reagent will give a CIS-product when reacted with an alkyne?

Answer 15

1. H2, Pd/BaSO4, Quinoline (lindlar’s catalyst)
2. a)BH3 b)CH3COOH

both produce cis products.

Question 16

Epimers

Answer 16

Stereoisomer of another compound that has different configuration at only ONE of several sterogenic centers.

Question 17

Oligodendrocytes

Answer 17

Produce myelin in the central nervous system

Question 18

Schwann Cells

Answer 18

Produce myelin in the peripheral nervous system

Question 19

Nodes of Ranvier

Answer 19

Gaps between segments of myelin

Question 20

Resting potential

Answer 20

At rest a neuron is POLARIZED at -70 millivots.

Which means that the inside is MORE NEGATIVE than the outside.

Due to ionic permeability of the neuronal cell membrane and is maintained by active transport by Na+/K+ pump.