Fusicoccin Ring System by [4 + 4] Cycloaddition. Control of Diastereoselectivity through Hydrogen Bonding

Fusicoccin Synthesis by Intramolecular [4+4] Photocycloaddition of 2-Pyridones: Stereocontrol of the Cycloaddition and Elaboration of the Pentacyclic Product

“…Nevertheless, the ready availability of intermediate 16 made evaluation of its properties straightforward. The stereoselectivity of 16 proved to be highly responsive to the reaction solvent, 17 the first substantial solvent dependency found for any 2-pyridone photocycloaddition. In addition, the stereoselectivity was also affected by the concentration of 16.…”

Photocycloaddition in Natural Product Synthesis

“…The groups of Sieburth and West have made extensive studies of the [4+4] photocycloaddition as a method for the construction of cyclooctanoid‐containing natural products. Sieburth has reported model studies for the synthesis of fusicoccin A using an intramolecular 2‐pyridone [4+4] photocycloaddition 109,110. Irradiation of the photosubstrate 162 was expected to promote a cis ‐selective cycloaddition that would set the stereochemistry of the methyl groups at C7 and C11.…”

Total Synthesis of (±)-Jujuyane

“…While there have been many cycloaddition routes to cyclooctanoids developed, , the unique characteristics of eight-membered ring structures, such as a flexible conformation and severe transannular interaction, casts formidable challenges to the synthesis of those natural products. Though cycloaddition reactions render facile construction of the eight-membered ring core structure, limited functional group manipulation options on the cycloaddition products has hindered application of cycloaddition reactions to the total synthesis of natural products . Though the oxidopyrylium dimerization reaction rapidly forges an eight-membered carbocyclic structure in a regio- and stereoselective manner, application of the oxidopyrylium dimer to natural product total synthesis has not yet been realized …”