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Synthesis of 7-azabicyclo[2.2.1]heptane derivatives by transformation of tropinone

✍ Scribed by Elena Gómez-Sénchez; José Marco-Contelles

Publisher
Journal of Heterocyclic Chemistry
Year
2006
Tongue
English
Weight
306 KB
Volume
43
Category
Article
ISSN
0022-152X

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✦ Synopsis

Abstract

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The bromination (CuBr~2~, AcOEt/CHCI~3~) plus Favorskii rearrangement (EtONa, EtOH) of N‐carbethoxytropinone (4), readily available from tropinone (3), affords mixtures of exo‐ and endo‐isomers of 2,7‐dicarbethoxy‐7‐azabicyclo[2.2.1]heptane (1b) in variable and moderate chemical yield (maximum 37%). The bromination (Br~2~, HBr/AcOH) reaction of compound 4 gives ethyl trans‐2,4‐dibromo‐3‐oxo‐8‐azabicyclo[3.2.1]octane‐8‐carboxylate (5) in 99% yield, a product that on Favorskii rearrangement (EtONa/EtOH) affords ethyl 2,2‐diethoxy‐3‐oxo‐8‐azabicyclo[3.2.1]octane‐8‐carboxylate in moderate yield (6) (52%).

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Absolute Configuration of 3-Substituted
Absolute Configuration of 3-Substituted 1-Azabicyclo[2.2.1]heptanes
✍ Jakob Boelsterli; Ursula Eggnauer; Esteban Pombo-Villar; Hans-Peter Weber; Malco 📂 Article 📅 1992 🏛 John Wiley and Sons 🌐 German ⚖ 396 KB

The l-azabicyclo[2.2. I]heptan-3-exo-ol (2) was resolved by fractional crystallisation of its hydrogen tartrate salts. The enantiomers (+)-and (-)-2 were oxidised to the ketones (-)-4 and (+)-4, respectively (Scheme). CD spectroscopy suggested that (-)-4 possesses the (IR,4S)-configuration. This abs