Diels-Alder	butadiene + ethylene	C1C=CCCC1
Diels-Alder	butadiene + butadiene	C1C=CCCC1C=C, C1C=CCC(C=C)C1, C1C(C=C)CC=CC1, C=CC1CCC=CC1
Diels-Alder	acetic acid + ethanol	
Diels-Alder	butene + Br2	
Electrocyclic_4e	butadiene + ethylene	C1C=CC1.C=C
Electrocyclic_4e	butadiene + butadiene	C1C=CC1.C=CC=C, C=CC=C.C1C=CC1
Electrocyclic_4e	acetic acid + ethanol	
Electrocyclic_4e	butene + Br2	
Esterification	butadiene + ethylene	
Esterification	butadiene + butadiene	
Esterification	acetic acid + ethanol	CC(=O)OCC.O
Esterification	butene + Br2	
Bromination	butadiene + ethylene	
Bromination	butadiene + butadiene	
Bromination	acetic acid + ethanol	
Bromination	butene + Br2	CC(C(C)Br)Br