Organic chemistry

Question 1

Constitutional isomerism

Answer 1

• aka Structural isomerism
• Molecules that contain the same atoms but connected in different ways -They have different physical and chemical properites.

Question 2

Conformational isomerism

Answer 2

• aka. stereoisomer
• Conformational isomerism arises because rotation is possible about sigma bonds.
• Allowing molecules to adopt a variety of shape.

Question 3

Aliphatic

Answer 3

An organic compound whose structure does not contain benzene or similar structure

Question 4

The NuE Method analysis

Answer 4

Question 5

Markonikoff rule

Answer 5

Question 6

Anti-markonikoff rule

Answer 6

Question 7

Alkene Reaction Pathway 1:

Carbocation Pathway overview

Answer 7

Question 8

Alkene Reaction Pathway 1:

Carbocation Pathway full explanation

Answer 8

Question 9

Describe

SN2 reaction

Answer 9

• (substitution, nucleophilic, bimolecular) is one where a collision between the two reacting species is involved in the rate determining step.

Nu: + Sub-LG —> Nu-Sub + LG¨

• the SN2 reaction is favored in the order 1° > 2° > 3°

Question 10

Good nucleophilic

Answer 10

• weak bases
• I¨, Br¨, RS¨, HS¨, N₃¨, RNH₂, CN¨ and PPh₃.

Question 11

SN2 reaction pathway mechanism

Answer 11

concerted mechanism- all the bond making and bond breaking occur simultaneously.

• The transition state has a planar arrangement about the Me, Et and H groups. There are partial negative charges on CN and Cl. Because of the backside attack of the nucleophile, there is a stereochemical (Walden) inversion at carbon in the product.

Question 12

Carbocation stabilitation

Answer 12

• Neighboring carbon atoms.
• Neighboring carbon-carbon multiple bonds
• Neighboring atoms with lone pairs.

Question 13

Carbocations are stabilized by neighboring carbon atoms

Answer 13

Question 14

Carbocations are stabilized by neighboring carbon-carbon multiple bonds

Answer 14

Question 15

Carbocations are stabilized by adjacent lone pairs

Answer 15

Question 16

Abbrevations for alkyl group

Answer 16

Question 17

Hidden hydrogen

Answer 17

The key thing in recognizing hidden hydrogens is that wherever you see less than 4 bonds to carbon, that carbon is going to have hydrogens attached such that there’s a full octet.

Question 18

Hidden lone pair

Answer 18

Question 19

Hidden charges

Answer 19

Question 20

Alkene mechanism pathway reaction 2

Formation of a 3-membered ring

Answer 20

Question 21

Alkene reaction pathway mechanism 3

The concerted pathway

Answer 21

Question 22

Summary of alkene reaction

Answer 22

Question 23

Acyl group

Answer 23

Question 24

Why are acyl chloride easily attacked by nucleophile?

Answer 24

Question 25

Nomenclature of ether

Answer 25

Question 26

The role of the hydroxide ion in a substitution reaction

Answer 26

* OH^- acts as Nu * For example, one of the lone pairs on the oxygen can attack the slightly positive carbon. This leads on to the loss of the bromine as a bromide ion, and the -OH group becoming attached in its place.

Question 27

The role of the hydroxide ion in an elimination reaction

Answer 27

* OH^- acts as strong base * the hydroxide ion hits one of the hydrogen atoms in the CH3 group and pulls it off. This leads to a cascade of electron pair movements resulting in the formation of a carbon-carbon double bond, and the loss of the bromine as Br-.

Question 28

pKa table

Answer 28

Question 29

What makes a good leaving group?

Question 30

3 classes of nucleophile

Answer 30

* lone pair * pi bond * sigma bond

Question 31

Evaluating resonance with positve charges

Answer 31

Question 32

Evalutating resonance with negative charges

Answer 32