- Acetoacetic Ester Synthesis
- Achmatowicz Reaction
- Acyloin Condensation
- Acyloin Rearrangement
- Adams Decarboxylation
- Akabori Amino Acid Reaction Type 1
- Akabori Amino Acid Reaction Type 2
- Albright−Goldman Oxidation
- Alder−Ene Reaction
- Aldol Condensation
- Algar−Flynn-Oyamada Reaction
- Alkene Metathesis
- Alkyne Zipper Reaction
- Allan−Robinson Condensation
- Allylic Rearrangement
- Amadori Rearrangement
- Angeli−Rimini Reaction
- ANORC Rearrangement Type 1
- ANORC Rearrangement Type 2
- Appel Reaction
- Arens−van Dorp Synthesis
- Arndt−Eistert Synthesis
- Asinger Reaction
- Asinger Reaction (Degussa Modification)
- Aston−Greenburg Rearrangement
- Atherton−Todd Reaction
- Auwers Synthesis
- Aza−Claisen Rearrangement