(Z)-Ethyl 2-((2S,4R,5S)-4,5-Dihydroxy-2-methoxydihydro-2H-pyran-3(4H)-ylidene)acetate-13C3 is a by-product intermediate in synthesizing Patulin-13C3 (P206502), a labelled Patulin (PAT). It is a mycotoxin produced by certain species of Penicillium, Aspergillus, and Byssochlamys, is mainly found in ripe apple and apple products. Patulin-induced genotoxicity and modulation of glutathione in Hep G2 cells. Antibiotic.