6-diene 9 in the ratios of 75:25 and 50:50, respectively. On the other hand, these cyclizations proceeded readily in the presence of diethylaluminum chloride at − 78° and − 35° giving in high yield the trans-pyrrolidine 2 from 1 with 100% and from 9 with 89% diastereoselectivity.
的
吡咯烷2和10通过热烯反应在+ 70°和+ 180°从(获得Ž)-4-氮杂-1,6-二烯1和从(ê)-4-氮杂- 1,6 -二烯9的比例分别为75:25和50:50。另一方面,这些环化反应在
二乙基铝
氯化物存在下于-78°和-35°容易进行,从而高产率地从1(具有100%)和9(具有89%非对映选择性)反式
吡咯烷2。