title: Novel strategies for the synthesis of anthrapyran antibiotics: discovery of a new antitumor agent and total synthesis of (S)-espicufolin.
abstract: Two high-yielding strategies for the synthesis of 4H-anthra[1,2-b]pyran antibiotics have been developed giving access to novel antitumor agent (ED(50) 1.5 microm) and to (S)-espicufolin (3). A key step for the assembly of the tetracyclic 4H-anthra[1,2-b]pyran-4,7,12-trione skeleton is the nucleophilic addition of an aryl lithium species onto an aldehyde which allows the introduction of either an ynone or 1,3-diketo side chain, serving as precursors for an acid-catalysed cyclisation.
authors.affiliation: Institut für Organische und Biomolekulare Chemie, Georg-August-Universität, Tammannstrasse 2, 37077, Göttingen, Germany. ltietze@gwdg.de
authors.forename: Lutz F
authors.initials: LF
authors.lastname: Tietze
authors.forename: Kersten M
authors.initials: KM
authors.lastname: Gericke
authors.forename: Ramakrishna Reddy
authors.initials: RR
authors.lastname: Singidi
authors.forename: Ingrid
authors.initials: I
authors.lastname: Schuberth
mesh_terms: D000880:Anthraquinones / Q000138:chemical synthesis* / Q000737:chemistry; D000900:Anti-Bacterial Agents / Q000138:chemical synthesis* / Q000737:chemistry; D000970:Antineoplastic Agents / Q000138:chemical synthesis* / Q000737:chemistry; D045744:Cell Line, Tumor; D049109:Cell Proliferation / Q000187:drug effects; D004354:Drug Screening Assays, Antitumor; D006801:Humans; D015394:Molecular Structure; D011714:Pyrans / Q000138:chemical synthesis* / Q000737:chemistry; D013237:Stereoisomerism; D013329:Structure-Activity Relationship
chemical_list: D000880:Anthraquinones; D000900:Anti-Bacterial Agents; D000970:Antineoplastic Agents; D011714:Pyrans; C102439:espicufolin