Classes of Organic Compounds: Part One

What are Functional Groups?

Halides:

• Functional Group: 
• -F, -Cl, -Br, -I 
• General Formula:  
• R-X
• Naming:  
• Name the parent chain (methane, ethane, propane...) 
• Name halogen groups as side chains (fluoro-, chloro-, bromo-, iodo-)
• Name other side chains
• Examples:  
• CH₃Br --> bromomethane 
• CCl₄ --> tetrachloromethane 
• H₂FCCHFCH₂CH₃ --> 1,2-difluorobutane 
• CH₃CHFCHFCH₃  --> 2,3-difluorobutane

• Above diagram --> trichloromethane  

• Above diagram  --> 1,2-dichlorobenzene

Alcohol:

• Functional Group: 
• -OH 
• General Formula:  
• R-OH
• Naming:  
• Name the parent chain (methane, ethane, propane...) 
• Substitute the "-e" ending with "-ol" (propanol, butanol, pentanol...) 
  •  
• Name other side chains
• Number the locations of the "-OH" on the structure
• Examples:  
• C₆H₅CH₂OH --> benzyl alcohol 
• CH₃ OH --> methanol (methyl alcohol) 

• Above diagram --> cyclohexanol

• Above diagram  --> ethanol (ethyl alcohol)

Ether: 

• Functional Group: 
• -O- 
• General Formula:  
• R-O-R'
• Naming:  
• Visualize the oxygen interrupting the structure, so there are going to be three pieces (in the most basic forms)  
• The first part of the structure (for this, we use the side chain prefix: meth-, prop-...) 
• The interrupting oxygen (list it as "oxy") 
• The last part of the structure (for this, we name it as the parent chain: methane, ethane)
• Combine the first part and the oxygen into one term (methoxy, propoxy) 
• And list the final piece as a parent chain (methoxy-methane, propoxy-ethane)
• Examples:  
• C₃H₈O --> methoxy-ethane 
• C₄H₁₀O--> methoxy-propane
• C₅H₁₂O --> methoxy-butane 

• Above diagram --> propoxy-pentane  

• Above diagram  --> methoxy-pentane

Aldehyde:

• Naming:  
• Name the parent chain (methane, ethane, propane...) 
• Substitute the "-e" ending with "-al" (propanal, butanal, pentanal...) 
   
  •  
• Name other side chains
• Number the locations of the "-OH" on the structure
• Examples:  
• CH₃ CHO --> ethanal 
• HCHO --> methanal
• _CH3CH2CHO --> propanal 

• Above diagram --> nonanal  

• Above diagram  --> pentanal

Ketone:

• Naming:  
• Take the prefix of the parent chain (metha-, etha-, propa-...) 
• End with the suffix, "-none" (methanone, ethanone, propanone...) 
   
  •  
• Name other side chains
• Number the locations of the double-bonded oxygen on the structure
• Examples:  
• C₇H₁₄O --> 3-heptanone 
• _C10H20O --> 2-heptanone

• Above diagram --> 2-heptanone  

• Above diagram  --> 3-nonanone

Carboxylic Acid: 

• Naming:  
• Name the parent chain (methane, ethane, propane...) 
• Substitute the "-e" ending with"-oic acid" (methanoic acid, ethanoic acid, propanoic acid...)  
•  
• Name other side chains
• Number the locations of the "-OH" on the structure
• Examples:  
• CH₃CO2H--> acetic acid (ethanoic acid) 
• _C8H16O2 --> octanoic acid 
• _C10H20O2 --> decanoic acid 
• _C4H8O2  --> butanoic acid

• Above diagram --> nonanoic acid  

• Above diagram  --> propanoic acid 

-Simon Sierra