Synthesis of C-17-functionalized spongiane diterpenes: diastereoselective synthesis of (-)-spongian-16-oxo-17-al, (-)-acetyldendrillol-1, and (-)-aplyroseol-14.
The diastereoselective synthesis of spongiane diterpenes (-)-spongian-16-oxo-17-al 2, (-)-acetyldendrillol-1 15, and (-)-aplyroseol-14 16 has been completed efficiently via the common intermediate 14. Compound 14 was prepared in five synthetic steps from (+)-podocarp-8(14)-en-13-one 13, easily available from commercial (-)-abietic acid. The key steps in the syntheses were a regioselective reduction of a 1,4-dialdehyde unit, a one-pot acetalization-acetylation, and a translactonization. The synthesis of 15 and 16 has led us to a revision of the configuration at C-17 for natural (-)-acetyldendrillol-1 and a structural reassignment for aplyroseol-14. Thus, aplyroseol-14 16 presents an unprecedented delta-lactone-based structure for spongiane-type diterpenoids. A theoretical study including a series of ab initio calculations for the mechanism involved in the conversion of ester 22 into natural product 2 has also been carried out.
Arnó
Manuel
M
Departamento de Química Orgánica, Facultad de Química, Universidad de Valencia, C/Dr. Moliner 50, E-46100 Burjassot, Valencia, Spain.
González
Miguel A
MA
Zaragozá
Ramón J
RJ
D045784:Abietanes; D000818:Animals; D000970:Antineoplastic Agents / Q000138:chemical synthesis* / Q000494:pharmacology; D000998:Antiviral Agents / Q000138:chemical synthesis* / Q000494:pharmacology; D002384:Catalysis; D004224:Diterpenes / Q000138:chemical synthesis* / Q000737:chemistry / Q000494:pharmacology; D006367:HeLa Cells / Q000187:drug effects; D018258:Herpesvirus 2, Human / Q000187:drug effects; D006801:Humans; D007202:Indicators and Reagents; D008958:Models, Molecular; D008968:Molecular Conformation; D015394:Molecular Structure; D019906:Nuclear Magnetic Resonance, Biomolecular; D010616:Phenanthrenes / Q000737:chemistry; D011161:Porifera / Q000737:chemistry; D013237:Stereoisomerism; D014407:Tumor Cells, Cultured / Q000187:drug effects
D045784:Abietanes; D000970:Antineoplastic Agents; D000998:Antiviral Agents; D004224:Diterpenes; D007202:Indicators and Reagents; D010616:Phenanthrenes; C477850:acetyldendrillol-1; C477851:aplyroseol-14; C477849:spongian-16-oxo-17-al; C023710:abietic acid