Total Synthesis of (±)‐Taiwaniaquinol B through a Sequence of Fries Rearrangement and Photo‐Nazarov Cyclization

Abstract

Described is a concise route to (�)-taiwaniaquinol B. The 6-5-6-fused ring system was constructed by sequencing a Fries rearrangement and a photo-Nazarov cyclization.The application of photoirradiation conditions was found to be crucial for promoting the key electrocyclization and mitigating the competing oxo-Michael pathway.

Total synthesis of (±)-mersicarpine following a 6-exo-trig radical cyclization

“…In addition to the known synthesis practices, the Usui group recently disclosed that mersicarpine is a novel protein translation inhibitor, and the bioactivity profile will conceivably stimulate further interest in the title natural product. 3 In concert with our continuing interest in the construction of aryl-substituted quaternary centers, 4 our initial plan is to establish compound 2 bearing an 2-indolyl quaternary carbon as a viable intermediate en route to mersicarpine. We sought to assemble 2 by a 6- exo-trig radical cyclization of a 2-halo- N -acyl indole derivative 3 (Scheme 1), 5 and the halogen substituent in 3 would function as a handle for the generation of an indolyl C2-radical.…”