prepared from (+)-pseudoephedrine and (–)-ephedrine for application in the stereoselective synthesis of the ketone ring of 1. Diels–Alder reaction of 9b with methyl acrylate in aqueous media, followed by selective ether bridge cleavage, has allowed access to the cyclohexenone 17 with preservation of stereochemistry at C2. A model route to the lactone ring has also been achieved through a one-pot decon
Salvinorin A 1 是一种来自墨西哥鼠尾草 S. divinorum 的具有精神活性的新
氯丹二萜,作为一种选择性 κ-阿片受体激动剂引起了人们的兴趣。非外消旋 3-
呋喃胺 9a 和 9b 已由 (+)-伪
麻黄碱和 (-)-
麻黄碱制备,用于立体选择性合成 1 的酮环。 9b 与
丙烯酸甲酯在
水性介质中的 Diels-Alder 反应,其次是选择性醚桥裂解,允许获得
环己烯酮 17,并在 C2 处保留立体
化学。通过 2-
溴巴豆酰氯 20 到
呋喃醇 19 的一锅解共轭/酯化过程,然后是 Reformatski 介导的闭环,还实现了通往内酯环的模型路线。