title: Total synthesis of (+)-geldanamycin and (-)-o-quinogeldanamycin: asymmetric glycolate aldol reactions and biological evaluation.
abstract: The total synthesis of (+)-geldanamycin (GA), following a linear route, has been completed using a demethylative quinone-forming reaction as the last step. Key steps include the use of two new asymmetric boron glycolate aldol reactions. To set the anti-C11,12 hydroxymethoxy functionality, (S,S)-5,6-bis-4-methoxyphenyldioxanone 8 was used. Methylglycolate derived from norephedrine 5 set the C6,7 methoxyurethane stereochemistry. The quinone formation step using nitric acid gave the non-natural o-quino-GA product 55 10:1 over geldanamycin. Other known oxidants gave an unusual azaquinone product 49. o-Quino-GA 55 binds Hsp90 with good affinity but is less cytotoxic compared to GA.
authors.affiliation: Brigham Young University, Department of Chemistry and Biochemistry, C100 BNSN, Provo, Utah 84602-5700, USA. mbandrus@chem.byu.edu
authors.forename: Merritt B
authors.initials: MB
authors.lastname: Andrus
authors.forename: Erik L
authors.initials: EL
authors.lastname: Meredith
authors.forename: Erik J
authors.initials: EJ
authors.lastname: Hicken
authors.forename: Bryon L
authors.initials: BL
authors.lastname: Simmons
authors.forename: Russell R
authors.initials: RR
authors.lastname: Glancey
authors.forename: Wei
authors.initials: W
authors.lastname: Ma
mesh_terms: D000447:Aldehydes / Q000737:chemistry*; D000970:Antineoplastic Agents / Q000138:chemical synthesis* / Q000737:chemistry / Q000494:pharmacology; D016227:Benzoquinones; D002470:Cell Survival / Q000187:drug effects; D006801:Humans; D020128:Inhibitory Concentration 50; D047029:Lactams, Macrocyclic; D015394:Molecular Structure; D011809:Quinones / Q000138:chemical synthesis* / Q000737:chemistry / Q000494:pharmacology; D013237:Stereoisomerism; D013329:Structure-Activity Relationship; D014407:Tumor Cells, Cultured
chemical_list: D000447:Aldehydes; D000970:Antineoplastic Agents; D016227:Benzoquinones; D047029:Lactams, Macrocyclic; D011809:Quinones; C469616:quinogeldanamycin; C116609:3-hydroxybutanal; C001277:geldanamycin