title: Toward the total synthesis of hygrocin B and divergolide C: construction of the naphthoquinone-azepinone core.
abstract: A highly regioselective Diels-Alder approach toward the bioactive natural products hygrocin B and divergolide C is presented. The route uses an unusual benzoquinone-azepinone dienophile prepared in 8 steps from ethyl 8-methoxy-1-naphthoate, by a route which includes, as key steps, a Birch alkylation and a Beckmann rearrangement of a tetralone oxime, both of which are demonstrated on multigram scale. The naphthoquinone-azepinone core is suitably functionalized for addition of the ansa-chain, found in the natural products.
authors.affiliation: School of Chemistry, University of Nottingham, University Park , Nottingham NG7 2RD, U.K.
authors.forename: Christopher C
authors.initials: CC
authors.lastname: Nawrat
authors.forename: Russell R A
authors.initials: RR
authors.lastname: Kitson
authors.forename: Christopher J
authors.initials: CJ
authors.lastname: Moody
mesh_terms: D000478:Alkylation; D001381:Azepines / Q000138:chemical synthesis* / Q000737:chemistry; D016227:Benzoquinones / Q000737:chemistry*; D001688:Biological Products / Q000138:chemical synthesis* / Q000737:chemistry; D047029:Lactams, Macrocyclic / Q000138:chemical synthesis* / Q000737:chemistry; D018942:Macrolides / Q000138:chemical synthesis* / Q000737:chemistry; D015394:Molecular Structure; D009285:Naphthoquinones / Q000138:chemical synthesis* / Q000737:chemistry; D010091:Oximes / Q000737:chemistry; D013237:Stereoisomerism
chemical_list: D001381:Azepines; D016227:Benzoquinones; D001688:Biological Products; D047029:Lactams, Macrocyclic; D018942:Macrolides; D009285:Naphthoquinones; D010091:Oximes; C583120:divergolide C; C506976:hygrocin B