Alcohol
-OH (hydroxy group)
Alkyne
triple bond
Amide
-CONH2, -CONHR, -CONR2
Amine
-NH2 (amino group)
Anhydride
Arene
aromatic ring
Carboxylic acid
-COOH
Ester
-COOR
Ether
-OR (alkoxy group)
Ketone
-C=O (carbonyl group)
hydroxyl
R-OH
Ketone
RCOR
Thiol
R-SH
Sulfide
R-S-R
acyl halide