structure of 2,4-dibromo-3,7-dicyanosemibulvalene(3b) synthesized from the bicyclo [3.3.0]octanedione 4 was determined by X-ray analysis; 3b exhibits a higher activation barrier towards degenerate Cope rearrangement than the parent semibullvalene.
                                    通过X射线分析确定了由双环[3.3.0]辛二酮4合成的2,4-二
溴-3,7-二
氰基半球
戊烯(3b)的晶体和分子结构;图3b显示的对简并Cope重排的活化障碍比母体半牛
戊烯高。