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

Abstract

The synthesis of halogenated bicyclo[4.2.01 inositols (and/or tetrols) are described. The photooxygenation of trans-7,8-dibromobicyclo[4.2.01octa-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. (C) 2020 Elsevier Ltd. All rights reserved.