The double Michael addition of benzylamine to 3-alkyl-2,7-cyclooctadienones, followed by hydrogenolysis, affords bridgehead substituted 9-azabicyclo[3.3.1]nonan-3-ones. Use of (+)-α-methylbenzylamine in the addition leads to mixtures of diastereomeric adducts in unequal amounts. Although the degree of asymmetric induction is low (10–20% ee), the diastereonomers can be easily separated, affording pure
将
苄胺双迈克尔加成至3-烷基-2,7-
环辛二烯酮,然后进行
氢解,得到桥头取代的9-
氮杂双环[3.3.1]壬基-3-
酮。在加成物中使用(+)-α-
甲基苄基胺会导致不等量的非对映异构体加合物的混合物。尽管不对称诱导的程度很低(10–20%ee),但非对映异构体可以轻松分离,从而提供了瓢虫
生物碱阿达林1和大戟
生物碱3的纯对映体形式。