Biomaterial Database

Total synthesis of the spirocyclic imine marine toxin (-)-gymnodimine and an unnatural C4-epimer. 2011

Ke Kong, and Ziad Moussa, and Changsuk Lee, and Daniel Romo

Department of Chemistry, Texas A&M University, P.O. Box 30012, College Station, Texas 77842-3012, USA.

The first total synthesis of the marine toxin (-)-gymnodimine (1) has been accomplished in a convergent manner. A highly diastereo- and enantioselective exo-Diels-Alder reaction catalyzed by a bis-oxazoline Cu(II) catalyst enabled rapid assembly of the spirocyclic core of gymnodimine. The preparation of the tetrahydrofuran fragment utilized a chiral auxiliary based anti-aldol reaction. Two major fragments, spirolactam 56 and tetrahydrofuran 55, were then coupled through an efficient Nozaki-Hiyama-Kishi reaction. An unconventional, ambient temperature t-BuLi-initiated intramolecular Barbier reaction of alkyl iodide 64 was employed to form the macrocycle. A late stage vinylogous Mukaiyama aldol addition of a silyloxyfuran to a complex cyclohexanone 83 appended the butenolide, and a few additional steps provided (-)-gymnodimine (1). A diastereomer of the natural product was also synthesized, C4-epi-gymnodimine (90), derived from the vinylogous Mukaiyama aldol addition.

UI	MeSH Term	Description	Entries
D007097	Imines	Organic compounds containing a carbon-nitrogen double bond where a NITROGEN atom can be attached to HYDROGEN or an alkyl or aryl group.	Imine
D008387	Marine Toxins	Toxic or poisonous substances elaborated by marine flora or fauna. They include also specific, characterized poisons or toxins for which there is no more specific heading, like those from poisonous FISHES.	Marine Biotoxins,Phycotoxins
D010080	Oxazoles	Five-membered heterocyclic ring structures containing an oxygen in the 1-position and a nitrogen in the 3-position, in distinction from ISOXAZOLES where they are at the 1,2 positions.	Oxazole,1,3-Oxazolium-5-Oxides,Munchnones,1,3 Oxazolium 5 Oxides
D010125	Ostreidae	A family of marine mollusks in the class BIVALVIA, commonly known as oysters. They have a rough irregular shell closed by a single adductor muscle.	Oysters,Oyster
D002384	Catalysis	The facilitation of a chemical reaction by material (catalyst) that is not consumed by the reaction.	Catalyses
D003300	Copper	A heavy metal trace element with the atomic symbol Cu, atomic number 29, and atomic weight 63.55.	Copper-63,Copper 63
D006575	Heterocyclic Compounds, 3-Ring	A class of heterocyclic compounds that include a three-ring fused structure. Both aromatic or non-aromatic ring structures are included in this category.	Fused Heterocyclic Compounds, Three-Ring,Heterocyclic Cpds, 3 Ring,Three Ring Heterocyclic Compounds,3-Ring Heterocyclic Compounds,Fused Heterocyclic Compounds, Three Ring,Heterocyclic Compounds, 3 Ring
D006844	Hydrocarbons, Cyclic	Organic compounds composed exclusively of carbon and hydrogen forming a closed ring that may be either alicyclic or aromatic.	Cyclic Hydrocarbons,Hydrocarbons, Polycyclic,Polycyclic Hydrocarbons
D000818	Animals	Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA.	Animal,Metazoa,Animalia
D013237	Stereoisomerism	The phenomenon whereby compounds whose molecules have the same number and kind of atoms and the same atomic arrangement, but differ in their spatial relationships. (From McGraw-Hill Dictionary of Scientific and Technical Terms, 5th ed)	Molecular Stereochemistry,Stereoisomers,Stereochemistry, Molecular,Stereoisomer