Bisketenes bromination

The bromination and hydrolysis of ketenes and bisketenes have been studied. The reaction of the bis(ketene) 289 with bromine has yielded the dibromo fumarate derivative 290, whose /r/mr-con figuration has been confirmed by X-ray crystallography (Scheme 41).366 The hydrolysis of the dibromo fumarate derivative 291 first provided the dibromo derivative (5//)-furanone 292. The prolonged reaction with water afforded the maleic anhydride 293. The methanolysis of the dibromo fumarate derivative 290 has resulted in the formation of an isomeric mixture of dimethyl... 

Addition of bromine to bisketene (Mc3SiC=C=0)2 (39) has been shown to produce the fumaryl dibromide (ii)-(40), which rearranged upon warming to furanone... 

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