Desaminierungsreaktionen, 341) Diels-Alder-Reaktionen mit Methoxycyclopentadien, ein Weg zu 1-Methoxynorbornan-2-diazonium-Ionen
✍ Scribed by Kirmse, Wolfgang ;Loosen, Karin
- Publisher
- Wiley (John Wiley & Sons)
- Year
- 1981
- Tongue
- English
- Weight
- 295 KB
- Volume
- 114
- Category
- Article
- ISSN
- 0009-2940
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✦ Synopsis
Deamination Reactions, 34^1)^ Diels‐Alder Reactions of Methoxycyclopentadiene, a Route to 1‐Methoxynorbornane‐2‐diazonium Ions
A Mixture of 1‐ and 2 ‐methoxycyclopentadiene (7, 8) was prepared in four steps from cyclopentadiene. Diels‐Alder reaction of 7 + 8 with methyl acrylate produces a mixture of adducts from which the 1‐methoxy isomers (9, 11) were obtained by distillation. Separation by way of the iodo lactone 20, hydrogenation, and Curtius degradation afforded endo‐ and exo‐1‐methoxy‐2‐norbornylamin (14, 17) Nitrous acid deaminations of 14 yielded norpinan‐2‐one (21) and norbornan‐2‐one (22) in a 3:7 ratio whereas 17 gave 22 only. The results of the deamination reactions confirm the position of the methoxy groups and illustrate the superiority of diazonium precursors in the norborane → norpinane rearrangement.