Biomimetic Electrocyclization Reactions toward Polyketide‐Derived Natural Products

Synthesis of a Liphagal–Frondosin C Hybrid and Speculation on the Biosynthesis of the Frondosins

“…Deprotonation at C-10 would generate the o -quinone methide 13 , which could perhaps undergo an intramolecular vinylogous aldol reaction to give frondosin C ( 4 ), although stereoelectronic considerations might appear to disfavor such a transformation. Later experiments in this paper will indicate that an alternative mechanism is more likely for the biogenetic origin of frondosin C. A more obvious fate for the o -quinone methide 13 might be a 6π-electrocyclic reaction to form 14 . A third and final oxidation in the biosynthetic sequence would then give a quinone cation that could be trapped by water at C-17 to give frondosin D ( 5 ) or by methanol to give frondosin E ( 6 ).…”

Biomimetic Synthesis of the Apoptosis-Inducing Thiazinoquinone Thiaplidiaquinone A

“…Biomimetic synthesis, or synthesis inspired by biosynthetic consideration, is a powerful tool in organic chemistry and has been applied in numerous routes to complex natural products. , Within this rapidly expanding arena, pericyclic reactions (cycloadditions, electrocyclizations and sigmatropic rearrangements), long regarded as one of the cornerstones of synthesis, are playing an increasingly important role. − One subset of such processes, oxa-6π electrocyclizations, are of particular interest since they usually have low activation barriers, are often reversible, and are quite common in the biosynthesis of oxygen heterocycles such as chromenes from phenolic precursors . We now report the use of such a process in a total synthesis of the apoptosis-inducing marine metabolite thiaplidiaquinone A 1 , a structurally unique benzo[ c ]chromene quinone.…”

Progress of the discovery, application, and control technologies of chemical pesticides in China

“…Biomimetic synthesis is the synthesis and modification of the unique substances of specific plants, animals, and microorganisms, such as the unique substances generated in plants to avoid predation and competition, and the sex pheromones and aggregation pheromones generated in insects for attraction and aggregation. Using these natural substances and their metabolites, lead compounds were selected by activity screening, and then, the new pesticides were developed by structure identification, synthesis, and modification (Zhang 2006;Burnley 2011). Using this method, some compounds with novel structure, unique mechanism, and good environmental compatibility can be obtained (Jiang et al 2000).…”