Convergent Total Synthesis of Asimicin via Decarbonylative Radical Dimerization

Abstract

Asimicin (1) exhibits potent antitumor activity and comprises a central C2‐symmetric bis‐tetrahydrofuran and two aliphatic side‐chains, one of which terminates with (S)‐methyl‐2(5H)‐furanone. This work reports a convergent total synthesis of 1 in 17 steps from d‐gulose derivative 4. Decarbonylative radical‐radial homo‐coupling of α‐alkoxyacyl telluride 12 a efficiently produced the C2‐symmetric core 3‐SS, which was transformed into 1 through stepwise attachment of the two side‐chains and functional group manipulations.

Evidence for Polarity- and Viscosity-Controlled Pathways in the Termination Reaction in the Radical Polymerization of Acrylonitrile

“…This difference in turn suggests a necessity of care or possible changes in the compositions and physical properties of bulk PAN samples subjected to high-temperature processing in the industry. Furthermore, while the coupling reaction of two radicals has recently been recognized as an important synthetic reaction in polymer and organic synthesis, − ,− the scope of the reaction is still limited. This work would also shed new light on designing a highly efficient coupling reaction.…”

Evidence for Polarity- and Viscosity-Controlled Domains in the Termination Reaction in the Radical Polymerization of Acrylonitrile

“…Therefore, care must be taken due to the possible changes in the compositions and physical properties of PAN samples during processing, such as the molding process. Furthermore, while the coupling reaction of two radical species has recently been recognized as an important synthetic reaction in polymer and organic synthesis, [23][24][25][42][43][44][45] the scope of the reaction are still limited. This work would also shed a new light for designing highly efficient coupling reaction.…”

Convergent Assembly of Highly Oxygenated Natural Products Enabled by Intermolecular Radical Reactions

“…In the absence of radical acceptors, radical A dimerizes itself to form radical-radical homocoupling product 6 by doubling the number of functional groups. 22 This dimerization strategy was implemented in the total synthesis of asimicin (1). Alternatively, nucleophilic radical A adds to electron-deficient CC, CN, and CO bonds, and Et 3 B then plays an additional role as a radical terminator of the resultant radicals to produce the coupling adducts 8, 10, and 12, respectively.…”