Furanoid systems, preparation

To extend this powerful new dihydrofuran synthesis to more complex systems, related reactions with branched /1-dicarbonyl systems were investigated [20]. hi a similar fashion, the cfs-fused furanoids 40 and 41 were prepared from hexane-2,4-dione (37), ethyl isobutyryl acetate (38), and 2. These targets are important chiral synthons, since there are many natural products bearing ethyl and isopropyl residues on furanoid rings. The flexibility of this method was also tested with the aromatic /3-diketone 39 yielding furanoid 42, which is an important system for tetralone synthesis (Scheme 8). 

Furanoid glycals can be used in a stereoselective route to 2 -deoxy-p-D-iAr o-pentofuranosyl nucleosides, as illustrated by the case in Scheme 2, and I -deoxy-fi-D-arabino-hexofuranosyl systems were similarly prepared. ... 

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