Synthesis of compounds including cyclopropane ring: Selectivity in additions

As a result of reactions such as addition, cis diolization, esterification and bromination, thirteen compounds containing spirocyclopropane were synthesized from spiro[2,4]hepta-4,6-diene (5) as the starting compound. Among these compounds, seven compounds also have an additional cyclopropane ring. A 1,3-Dipolar cycloaddition reaction of the compound obtained from cycloheptatriene-PTAD, an adduct was selectively synthesized. Additionally, bromine was selectively added to the endo-ester, resultingthe reaction of 5 and ethyl diazoacetate. The rearranged product monobromo 12 was obtained from reaction molecular bromine with compound 7, The structure of its was determined by X-ray diffraction analysis. The structure of some compounds (9, 23 and 24) were also determined by X-ray diffraction analysis. Additionally, compound 27 was obtained as endo-selectivity.