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DOI: 10.1055/s-1996-5314
Temporary Sulfur Connection in an Intramolecular SN2-Reaction. A Stereocontrolled Synthesis of (±)-Kainic Acid
Publikationsverlauf
Publikationsdatum:
31. Dezember 2000 (online)
Homolytic isomerization of isocyanide 7 affords 2β-t-butoxycarbonyl-3β-(t9-butyldimethylsilyloxy)-4α-isopropenyl-5-ethylthio-4H-2,3-dihydropyrrole (8). The conversion of key intermediate 8 into (±)-kainic acid (3) involves, inter alia, temporary sulfur connection of an acetic acid moiety to the chiral isopropylene anchor, followed by its regio- and stereospecific intramolecular bonding to the pyrrolidine backbone. The acetic acid moiety is eventually disconnected from its anchor with concomitant regeneration of the isopropylene group by a new samarium(II) iodide-mediated tandem reductive elimination.
samarium(II) iodide - radical cyclization - tandem elimination - thiyl radical - alkenyl isocyanide