title: Total synthesis of cladocorans A and B: a structural revision.
abstract: Cladocorans A and B, isolated from the Mediterranean coral Cladocora cespitosa, are novel sesterterpenoids whose structures were initially proposed as 1 and 2, respectively. These designations, however, subsequently came under doubt. In the present study, the synthesis of compounds 5 and 6 was undertaken. The physical properties of 5 and 6 were found to be identical to those of natural cladocorans A and B, whose structures were thus concluded to be 5 and 6, respectively. Cladocoran B is thus clearly shown to be an olefinic regioisomer of dysidiolide and cladocoran A as its acetate.
authors.affiliation: School of Pharmacy, Tokyo University of Pharmacy and Life Science, 1432-1 Horinouchi, Hachioji, Tokyo 192-0392, Japan.
authors.forename: Hiroaki
authors.initials: H
authors.lastname: Miyaoka
authors.forename: Makoto
authors.initials: M
authors.lastname: Yamanishi
authors.forename: Yasuhiro
authors.initials: Y
authors.lastname: Kajiwara
authors.forename: Yasuji
authors.initials: Y
authors.lastname: Yamada
mesh_terms: D015107:4-Butyrolactone / Q000031:analogs & derivatives / Q000138:chemical synthesis / Q000737:chemistry / Q000302:isolation & purification; D000818:Animals; D037421:Anthozoa / Q000737:chemistry*; D007202:Indicators and Reagents; D008522:Mediterranean Sea; D015394:Molecular Structure; D019906:Nuclear Magnetic Resonance, Biomolecular; D013237:Stereoisomerism
chemical_list: D007202:Indicators and Reagents; C479318:cladocoran A; C121906:dysidiolide; D015107:4-Butyrolactone