A facile, efficient, and scalable synthesis of optically pure coronafacic acid by resolution of racemic coronafacic acid obtained using an improved version of Watson's method has been developed. By optimizing the boron‐mediated aldol reaction of Watson, we were able to prepare 2.1 g of racemic coronafacic acid. This was coupled with (S)‐4‐isopropyl‐2‐oxazolidinone to give a mixture of diastereomeric
syntheses of four stereoisomers of coronatine employing the exo-selectiveDiels–Alder reaction as a key step. Remarkable differences in stomatal opening activity were observed between enantiomers of coronatine. This result strongly suggests that the stereo structure of coronatine is very important for its stomatal opening activity. In addition, SAR studies suggested that coronatine operates as a molecular
derived mesylate was used to construct the side chain that was designed to afford the cyclohexene ring of coronafacic acid via intramolecular alkylation. Elimination of the mesylate proceeded with TBAF. The alkylation was achieved with t-BuOK in THF, and then hydrolysis afforded coronafacic acid, which upon condensation with unprotected l-isoleucine using ClCO2Bui furnished coronafacoyl-l-isoleucine, the
Coronafacic acid, the acidic component of coronatine, was synthesized via the stereospecific alkylation of the tricyclo[4,3,0,01.5]nonane derivative, followed by the fission of cyclopropane ring.