MCAT Nomenclature

Question 1

Describe the steps to naming an organic compound?

Answer 1

1. Choose the side with the highest priority, this will be carbon 1 and we find the parent chain which is the chain with the most number of carbons.
2. When writing name we place them in order of priority.

• -“ n” indicates a straight chain alkane.
• If double and triple bond ends in tie when numbering the double bond has higher priority.
• If multiple of the same substituents we use prefix of di, tri, tetra, etc..- Keep in mind these are not considered when naming.
• We separate numbers via commas and words via hyphens.*

Question 2

Describe alkanes?

Answer 2

Simple hydrocarbons with the formula CnH ( 2n+2)
1- methane
2- ethane
3- propane
4- butane
5- pentane
6- hexane
7- heptane
8- octane
9- nonane
10- decane
11- undecane
12- dodecane

Question 3

Describe the halogens as substituents

Answer 3

Florine- fluoro
Chlorine- chloro
Bromine- Bromo
Iodine- Iodo

Question 4

Alkenes and Alkynes

Answer 4

Alkenes = double bonds, Alkynes = triple bonds.

We name them as a substituent, denoting position of and the suffix.
- 2- butene
- 2,3- butadiene

Question 5

IUPAC naming of alcohols? Common naming?

Answer 5

IUPAC - dropping “e” of alkane and adding “ ol” as suffix.

Common naming - alkyl alcohol
- Alcohols with 2 OH groups are called diols or glycols ( with the suffix being diols).
* Vicinal diols - OH groups on carbons next to each other.
* Geminal diols- OH groups on the same carbon.

Question 6

How to name aldehydes and ketones?

Answer 6

Name aldehydes by placing the carbonyl carbon as carbon which starts the parent chain. Replace “ -e” with “- al”.

Name ketones by replacing “ - e” with “- one”.

Common naming is “ alkyl aldehyde” or “ alkyl ketone”

Question 7

How to name carbonyls as substituents.

Answer 7

We name aldehydes and ketones as “oxo”

Question 8

Numbering of carbons next to carbonyl carbon

Answer 8

Carbon next to carbonyl carbon is the alpha carbon, beta carbon, gamma, delta.

Question 9

How to name carboxylic acids?

Answer 9

Contains a carbonyl carbon with with a hydroxyl group.

Name by replacing “-e” with “-oic acid”.
This is highest functional group.

Question 10

What are esters and how to name them?

Answer 10

Derivatives are carboxylic acids in which an alkyl group replaces the hydrogen of the hydroxyl group.

Name by naming the alkyl group on the right and then replacing “ -e” with “- ate”.

Question 11

What are amides and how do we name them?

Answer 11

Amides are carboxylic acids with the hydroxyl group replaced with a nitrogen group attached to alkyl groups.

To name, first denote the alkyl groups on the nitrogen via “ n - alkyl-n- alkyl) and replace “ -e” of parent chain with “- amide”.

Question 12

What are anhydrides and to name them?

Answer 12

There two carboxylic acids attached to each other via dehydration reaction.

To name name right group adding “- oic” as the ending and then the left group with the same suffix. Name anhydride as the separate second word.