Having established a viable model for the unexpected isomerism of oxetane carboxylic acids to lactones[1], and taken a look at a variation in the proton transfer catalyst needed to accomplish the transformation, I now investigate the substrate itself.
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