BROMINATION

The bromination of condensed chromen-2-ones is carried out. The influence of medium on the reaction occurrence has been studied. In the acidic acid solution aromatization of the 4H-pyrane fragment or hydrogen atom substitution at the tertiary carbon atom takes place. In chloroform, addi­ tion of bromine by the double bond occurs. Mixture of tetrachloromethane and propanol-2 promotes the intermolecular dehydration with the formation of ether bond.

The examples of regiospecificity reactions of dienones derivatives of cyclohexane are made. On basis of 6-benzylidene -2-(5-nitrohetarilmetilidene) cyclohexanones were synthesized previously unknown dibromadducts, hexahydroindazoles and triazolochinazolines. The structure of derived compounds was ascertained by spectral methods. The probable reaction schemes are shown.