C3H4O2 may refer to:
Compounds sharing the molecular formula: Acrylic acid Malondialdehyde Methylglyoxal 3-Oxetanone Propiolactone isomers: Alpha-Propiolactone (α-propiolactone) Beta-Propiolactone (β-propiolactone)
Discovered by embedding cosine similarity (sentence-transformers MiniLM, 384-dim).