Synthesis of novel tetrols from syn-bisepoxide: Preparation of halogenated bicyclo[4.2.0] inositols

The synthesis of halogenated bicyclo[4.2.0] inositols (and/or tetrols) are described. The photooxygenation of trans-7,8-dibromobicyclo[4.2.0]octa-2,4-diene obtained using cyclooctatetraene as the starting molecule afforded the bicyclic endoperoxide. To obtain the halogenated bicyclo[4.2.0] inositols, the required key intermediate endoperoxide was rearranged quantitatively to the corresponding bisepoxide under thermal conditions. Ring-opening reaction of the bisepoxide with H+/Ac2O resulted in a mixture of tetraacetates as well as the formation of a cyclic sulfate. Eventually, the desired halogenated bicyclo[4.2.0] inositols (and/or tetrols) were obtained in high yield by ammonolysis of the acetate groups by NH3. The structures of all the synthesized compounds were characterized by spectroscopic methods. [Display omitted] •Concise synthesis of the halogenated bicyclo[4.2.0] inositols via ring-opening reaction of the bisepoxide with H+/Ac2O.•The formation of a cyclic sulfate from ring-opening reaction of the bisepoxide with H+/Ac2O.•Synthesis of novel tetrols from syn-bisepoxide.•The regio- and stereospecific first halogenated inositol derivatives which has conduritol framework was efficiently synthesized.