Thermodynamic equilibration in Pd(0)-catalyzed interconversion of highly constrained [2.1.2] bicyclic lactones: its mechanistic investigation

Divergent synthetic route to new cyclopenta[c]pyran iridoids: syntheses of jatamanin A, F, G and J, gastrolactone and nepetalactone

Six natural iridoids including jatamanin A, F, G and J, gastrolactone and nepetalactone have been synthesized via the efficient transformation of a core cyclopenta[c]pyran intermediate. Key features of the syntheses include the stereoselective construction of the core cyclopenta[c]pyran skeleton of the iridoid lactones via a Pd(0)-catalyzed intramolecular allylic alkylation, and the facile transformation of the common intermediate into natural iridoids.

Stereoselective synthesis of 7-epi-incarvilline

The enantioselective synthesis of 7-epi-incarvilline for formal syntheses of (-)-incarvilline, (+)-incarvine C, and (-)-incarvillateine is described. The key features of our synthesis involve (1) stereoselective construction of the optically active bicyclic lactone utilizing Pd(0)-catalyzed allylic alkylation, (2) efficient transformation of the bridged bicyclic lactone to the key bicyclic lactam skeleton, and (3) stereoselective elaborations of two stereocenters via a substrate-controlled catalytic hydrogenation and a 1,4-addition.