orgo fundamentals

Question 1

What kind of rex do these arrows indicate

Answer 1

a reversible reaction

Question 2

What does this full arrow from the oxygen to the carbon mean

Answer 2

The electrons on the oxygen are “attacking” the carbon atom. There is a transfer of 2 electrons (an electron pair) and formation of a bond between the carbon and oxygen.

Question 3

What do these half-headed arrows indicated

Answer 3

the transfer of a single electron

Question 4

what are nucleophiles and electrophiles

Answer 4

nucleophiles are electron donors (electron rich)

electrophiles are electron acceptors (are electron deficient)

Question 5

hydroxyl functional group formula and properties

Answer 5

R-OH

Hydroxyls can act as nucleophiles or electrophiles.

When hydroxyl is negative or neutral it is a nucleophile (NNN)

When hydroxyl is positively charged it is an electrophile.

Question 6

Carbonyl formula and derivatives and properties

Answer 6

C=O

derivatives are ketones and aldehydes

aldehydes are carbonyls with one R group attached to carbonyl carbon and carbonyl group is always at the end of the carbon chain

ketones have 2 R groups attached to the carbonyl carbon and are within the carbon chain

the carbonyl carbon is partially positive so it often acts as an electrophile

Question 7

carboxylic acid formula and properties

Answer 7

A carbonyl group attached to a hydroxyl and an R group

R-COOH

can act as both electrophiles and nucleophiles

carboxylic carbon is even more electrophilic than a normal carbonyl carbon because there are 2 oxygens pulling electron density away from it making it highly partially positive and a very strong electrophile.

Both oxygens can act as nucleophiles.

Question 8

carboxylic acid derivatives

Answer 8

anhydride -2 carbonyl groups linked together via an anhydride bond

-Ester
Carboxylic acid derivative where the Carbonyl carbon is bonded to an -OR’
instead of an -OH

Amide
-carboxyllic acid derivative where Nitrogen is bonded to carbonyl carbon instead of OH

Question 9

Amines formula and properties

Answer 9

R-N

The nitrogens in amines have high e- density so they can act as nucleophiles

Question 10

Sn1 vs Sn2 reactions

Answer 10

Both are nucleophilic substiuition reactions where a nucleophile attacks, and a leaving group leaves

Sn2 is a concerted mechanism meaning it occurs in one step.
- nucleophile attacks an electrophile and at the same time a leaving group leaves. Inversion of stereochemisty occurs due to steric hindrance of backside nucleophilic attack.

Sn1 occurs in 2 steps
1. Leaving group leaves forming a carbocation
2. Nucleophile atttacks carbocation and forms bond.
No inversion

Question 11

E1 vs E2 reactions

Answer 11

Elimination reactions which eliminate an atom and form a double bond.

E1 rxns take 2 steps
1. Leaving group leaves
2. hydrogen from adjacent carbon binds with a carbocation and leaves forming a double bond.

E2
- Nucleophile attacks hydrogen ion forming a double bond, which kicks off the leaving group