The First Example of the Stereoselective Synthesis of 7.BETA.-Carbamoyl-4,5.ALPHA.-epoxymorphinan via a Novel and Reactive .GAMMA.-Lactone
作者:Hideaki Fujii、Noriyuki Hirano、Hiromi Uchiro、Kuniaki Kawamura、Hiroshi Nagase
DOI:10.1248/cpb.52.747
日期:——
7alpha-carboxylate intermediate 3 in the presence of 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU) and amines under reflux conditions in mesitylene via a novel and reactive gamma-lactone 7. These were the first examples of the stereoselective syntheses of 7beta-substituted 4,5alpha-epoxymorphinans. The mechanism of the reaction process was elucidated as follows: 1) epimerization of 7alpha-carboxylate 3, 2) intramolecular
在1,8-二氮杂双环[5.4.0]十一碳-7-烯(DBU)和胺存在下,在1,8-二氮杂双环[5.4.0]十一碳-烯(DBU)和胺的存在下,通过7,3-氨基甲酸酯中间体5立体选择性地合成了7β-氨基甲酰基-4,5α-环氧吗啡喃5一个新颖的反应性γ-内酯7。这些是7β-取代的4,5α-环氧吗啡喃的立体选择性合成的第一个例子。阐明了反应过程的机理,如下:1)7α-羧酸盐的差向异构化3,2)7β-羧酸盐6的分子内内酯化,和3)所得γ-内酯7的氨解。内酯7和烯丙胺在室温下用NaBH(4)进行甲醇醇解。γ-内酯7可作为制备7β-取代的4的有用中间体 5α-环氧吗啡喃可能是有效的选择性δ阿片受体配体。从7α-羧酸盐3经由7α-羧酸合成7α-氨基甲酰基-4,5α-环氧吗啡喃9的立体选择性合成也很成功。