Photochemical Reduction of gem-Dihalocyclopropanes. III. Debromination of Some Compounds Containing Two 1,1-Dibromocyclopropane Moieties.
摘要:
2,2,2',2'-Tetrabromo-1-phenylbicyclopropyl and 1,1-dibromo-2-(2,2-dibromocyclopropyl)methyl-2-phenylcyclopropane have been synthesized, analyzed by X-ray crystallographic techniques, and exposed to acetone-sensitized irradiation. The former compound, which was obtained as a single diastereoisomer, gave a product mixture consisting of an undisclosed number of the corresponding tribromides resulting from reduction at either ring. The latter tetrabromide was separated into its diastereoisomers, which were irradiated separately. One of the diastereoisomers gave a mixture of tribromides caused by reduction at either ring, whereas the other isomer was reduced regioselectively at the phenyl-substituted ring and gave a mixture of cis- and trans-1-bromo-2-(2,2-dibromocyclopropyl) methyl-2-phenylcyclopropane.