Stereoselective synthesis of syn-meso-cyclooctanetetraol, bromo-, and oxabicyclic amino-alcohol derivatives

The first synthesis of syn-meso-cyclooctane-1,2,3,4-tetraol isomer, a new bromocyclooctanetriol, and oxabicyclic amino-alcohol derivatives of them starting from cis,cis-1,3-cyclooctadiene is described. For the construction of a cyclooctane-1,2,3,4-tetraol skeleton with all the syn hydroxyl groups, cyclooctene endoperoxide was used as the key compound. Epoxidation of the endoperoxide followed by hydrogenation of the peroxide group gave the corresponding syn-epoxy-diol, which was hydrolysed with HBr(g) in methanol to produce a bromotriol compound that is a potentially important cyclitol for the versatile synthesis of different cyclitols and aminocyclitols. Reaction of bromotriacetate with AgClO4 afforded the target syn-meso-tetrol as the sole product. Treated of azidoepoxide, which was the second key compound, with HBr(g) in methanol resulted in the unexpected formation of an oxabicyclic azido-alcohol derivative.