acetaldehyde if ethanol is ingested. Since acetaldehyde is toxic and can no longer be metabolized to the less toxic acetic acid, the characteristic symptoms of coprine poisoning occur. However, as shown in the mechanism below, the covalent bonding is reversible, which is what allows symptoms to subside if no more alcohol is consumed. 1-Aminocyclopropanol also deactivates the esterase activity of acetaldehyde dehydrogenase, but less significantly. Synthesis Coprine is the first discovered compound with a naturally occurring cyclopropanone group. Chemical synthesis can be effectively carried out by conducting an N-acylation reaction on 1-aminocyclopropanol. Treatment of isocyanatocyclopropane with hydrochloric acid leads to the hydrochloride of 1-aminocyclopropanol. Adding sodium hydroxide to create 1-aminocyclopropanol will destabilize the structure, so synthesis must be conducted using the hydrochloride. The addition of the hydrochloride to N-phthaloyl-L-glutamic anhydride will undergo acylation. Lastly, the blocking group is removed using hydrazine, yielding coprine. The enantiomer, isocoprine, is formed in negligible quantities in small-scale synthesis but is synthesized in higher amounts in large-scale, industrial synthesis. References Acetaldehyde dehydrogenase inhibitors Amino acid derivatives Cyclopropanes Mycotoxins