FR900482の全合成

抄録

This review focuses on total syntheses of antitumor antibiotic FR 900482. After a brief discussion of synthetic problems of this compound, the first racemic total synthesis of FR 900482 by Fukuyama is described, which provided some important insights for the designing synthetic route through the 8-membered N-hydroxybenzazocinone key intermediate. Then, recently disclosed total syntheses as well as formal total syntheses and synthesis of derivatives were described including Martin's formal total synthesis utilizing the Grubbs' olefin metathesis for the formation of benzazocin ring, Ciufolini's characteristic formation of benzazocin ring by a sequential reaction (intramolecular [1, 3] -dipolar cycloaddition of azide, photomediated conversion of triazorine to aziridine, and a fragmentation initiated by a homo-Brook rearrangement), Williams' total synthesis employing an intramolecular reductive amination to construct the benzazocin ring and an unusual deprotective oxidation of N-PMB group to form hydroxylamine, Paleo and Rapoport's formal synthesis taking convergent route using an epoxy α-amino acid segment derived from vinylglycin, and Fukuyama's synthetic approach using intramolecular [3+2] cycloaddition of nitrone and enantiospecific total synthesis utilizing a novel ketone synthesis and reductive intramolecular hydroxyamination.