1-(2-丁二烯基)吡啶溴化物的新的交叉型Diels-Alder反应

Novel crossed Diels-Alder Reactions of 1-(2-Butadienyl) Pyrinidium Bromide

一个带正电荷的二烯.1-（2-丁二烯基）毗啶溴化物（la），与环戊二烯在乙腈中发生的交叉型Diels-Alder环成反应，是立体专一和区域选择性反应。（la）的区城选择性作为亲双烯体是独特的。

Crossed Diels-Alder cyeIoadditions of a positively charged diene, 1 - (2 -butadienyl)pyridimium bromide (la), with cyclopentdienl in acetonitile proceed stereospecigfically and regioseletively The rgeioseleetivity of la as the dienophile is especially unigue