Biomimetic macrocycle-forming Diels-Alder reaction of an iminium dienophile: synthetic studies directed toward gymnodimine.
The macrocyclic core of gymnodimine has been constructed via an intramolecular Diels-Alder reaction of an alpha,beta-unsaturated iminium dienophile in water. The cycloaddition furnished a single exo-product, along with two endo-products. Through X-ray analysis of a suitable derivative, the stereochemistry of the exo-product was established, thereby demonstrating that its stereochemistry matches that of gymnodimine. In contrast, macrocyclization of an analogous alpha,beta-unsaturated ketone dienophile gave only undesired endo-products. Interestingly, the imine dienophile shows remarkable stability in water. [reaction: see text]
Johannes
Jeffrey W
JW
Department of Chemistry and Chemical Biology, Harvard University, 12 Oxford Street, Cambridge, MA 02138, USA.
Wenglowsky
Steve
S
Kishi
Yoshito
Y
D018360:Crystallography, X-Ray; D006575:Heterocyclic Compounds, 3-Ring / Q000138:chemical synthesis* / Q000737:chemistry; D006844:Hydrocarbons, Cyclic / Q000138:chemical synthesis* / Q000737:chemistry; D007097:Imines / Q000138:chemical synthesis / Q000737:chemistry*; D008968:Molecular Conformation; D015394:Molecular Structure
D006575:Heterocyclic Compounds, 3-Ring; D006844:Hydrocarbons, Cyclic; D007097:Imines; C407350:gymnodimine