Derek Lowe’s blog has a recent post entitled A Downside to Oxetane Acids which picks up on a recent article[1] describing how these acids are unexpectedly unstable, isomerising to a lactone at a significant rate without the apparent need for any catalyst. This is important because these types of compound occur frequently in the medicinal chemistry literature.
References
- B. Chalyk, A. Grynyova, K. Filimonova, T.V. Rudenko, D. Dibchak, and P.K. Mykhailiuk, "Unexpected Isomerization of Oxetane-Carboxylic Acids", Organic Letters, vol. 24, pp. 4722-4728, 2022. http://dx.doi.org/10.1021/acs.orglett.2c01402