Synthesis of Highly Oxygenated Bicyclic Carbasugars. Remarkable Difference in the Reactivity of the d-gluco and d-xylo- Derived Trienes

Stereoselective synthesis of novel bis-homoinositols with bicyclo[4.2.0]octane motifs

Starting from cyclooctatetraene, bis-homoconduritols with cis-inositol and allo-inositol (or bicyclo[4.2.0]octane motif) structures were synthesized. Photooxygenation of trans-7,8-dibromo-bicyclo[4.2.0]octa-2,4-diene allowed the preparation of tricyclic endoperoxide. The compound diacetate was obtained by reduction of endoperoxide with thiourea followed by acetylation reaction. Removal of halides with zinc dust in acetic acid yielded the dien-diacetate, a key compound of the designed molecules. OsO₄ oxidation of diendiacetate followed by acetylation gave the corresponding hexaacetates. Finally, the novel desired bis-homoinositols were obtained in high yield by the ammonolysis of acetate groups. The structures of all synthesized compounds were characterized by spectroscopic methods.