Zur-Reaktionsweise von Enaminen mit Cyclopropenonen III. Isolierung eines Produktes der «C, C-Insertion»
✍ Scribed by V. Bilinski; A. S. Dreiding
- Publisher
- John Wiley and Sons
- Year
- 1972
- Tongue
- German
- Weight
- 355 KB
- Volume
- 55
- Category
- Article
- ISSN
- 0018-019X
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✦ Synopsis
Abstract
From the reaction of the N‐(2‐Methylpropenyl)‐pyrrolidin 6 with diphenylcyclopropenone 7 we isolated as a byproduct 5‐Methyl‐2, 4‐diphenyl‐1‐pyrrolidino‐hexa‐1, 4‐diene‐3‐one 9. The structure was proven by an interpretation of the IR.‐, NMR.‐ and MS.‐spectra. This result is of importance since it represents the first case of a direct ‘C, C‐insertion’ product 4 from the reaction of an enamine 1 and a cyclopropenone 2 and because structures of type 4 (including 9) have previously been postulated for the main products of this reaction, which were later shown to be amides 3 (including 8).
Acid hydrolysis of the β‐amino‐dienone 9 yielded the dihydropyrone 10 and the cyclopentenone 11. These isomeric products are considered to be the result of two electrocyclic reactions, one of a hexa‐2,4‐diene‐al 12 and the other of a hexadienylium ion 14.