(1R,8S)-9. The reaction proceeds by a sequence of stereospecific steps from 5 to an equilibrating mixture of exo- and endo-isocyanates 6 and 7. The endo-isomer 7 undergoes Cope rearrangement to the putative intermediate 8, which is trapped and characterized as the adduct 9b of butan-1-ol. The absolute configuration of 9b was determined by its reduction to the amide 20, and determination of the X-ray
通过确定重排产物 (1R,8S)-9 的绝对构型来研究光学纯酰基
叠氮化物 (-)-(1S)-5 的热 2-aza-Cope 重排的立体
化学过程。该反应通过一系列立体定向步骤从 5 进行到外-和内-
异氰酸酯 6 和 7 的平衡混合物。内向异构体 7 经历 Cope 重排为推定的中间体 8,该中间体被捕获并表征为加合物 9b
丁烷-1-醇。9b 的绝对构型是通过将其还原为酰胺 20 来确定的,并确定源自已知绝对构型的
樟脑酸的 N-
樟脑酰胺 21 的 X 射线结构。