Synthetic studies toward the C5-C20 domain of the azaspiracids.
[structure: see text]. An approach toward the C5-C20 THF-fused trioxadispiroketal portion of the azaspiracids is reported. The highly substituted azaspiracid D ring (C16-C19) was prepared by the one-pot conversion of a tetraol into a tetrahydrofuran. Efforts to establish the C10 and C13 spiroketal centers via an oxonium-initiated bis-spiroketalization under both kinetic and thermodynamic conditions have yielded the (10R,13S)-trioxadispiroketal 19 as the major product, which is diastereomeric with the (10R,13R) relative configuration assigned to the azaspiracids.
Department of Chemistry, University of Minnesota, Minneapolis, Minnesota 55455, USA.
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Dounay
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CJ
Forsyth
D000818:Animals; D049872:Bivalvia / Q000737:chemistry*; D005663:Furans / Q000737:chemistry*; D006801:Humans; D008387:Marine Toxins / Q000737:chemistry*; D015394:Molecular Structure; D012997:Solvents / Q000737:chemistry; D013141:Spiro Compounds / Q000737:chemistry*; D000095702:Polyether Toxins
D005663:Furans; D008387:Marine Toxins; D012997:Solvents; D013141:Spiro Compounds; C406592:azaspiracid; D000095702:Polyether Toxins; C018674:tetrahydrofuran