Alternative pentalenene synthase cyclization pathways proceeding through the 7-protoilludyl cation intermediate C predicted by quantum chemical calculations65 and supported by experimentally-measured kinetic isotope effects.64 Reprinted with permission from: Zu, L., Xu, M., Lodewyk, M. W., Cane, D. E., Peters, R. J., & Tantillo, D. J. Effects of isotopically sensitive branching on product distribution for pentalenene synthase: support for a mechanism predicted by quantum chemistry. J. Am. Chem. Soc.
134, 11369–11371 (2012). Copyright 2012 American Chemical Society.