1,5-Sigmatrope Umlagerung von Diels-Alder-Addukten bei der Reaktion von Alkatrienphosphonaten mit Acetylencarbonsäureestern – Ein neuer Weg zur Synthese von Benzyl- und Phenylphosphonaten
✍ Scribed by Mondeshka, Diana ;Tancheva, Chonka ;Angelov, Christo
- Publisher
- Wiley (John Wiley & Sons)
- Year
- 1990
- Tongue
- English
- Weight
- 626 KB
- Volume
- 123
- Category
- Article
- ISSN
- 0009-2940
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✦ Synopsis
1,5‐Sigmatropic Rearrangements of Diels‐Alder Adducts in the Reaction of Alkatrienylphosphonates with Alkyl Acetylenecarboxylates ‐ A New Method for the Synthesis of Benzyl‐ and Phenylphosphonates
The reaction of dialkyl (3‐methyl‐1,2,4‐pentatrienyl)‐ and dialky] (3‐methyl‐1‐vinyl‐1,2‐butadienyl)phosphonic acids 1a–d an 5a, b, respectively, with alkyl esters of the acetylenecarboxylic acids 2a–d proceeds via 1,5‐sigmatropic rearrangement and aromatization of the initially formed Diels‐Alder adducts. The reaction with the unsymmetrical dienophiles 2a, b occurs with preferred formation of the cycloadducts A, leading to the benzylphosphonates 3a–h. The above reaction constitutes a new method for the preparation of difficulty accessible derivatives of the benzyl‐ and phenylphosphonic acids. The aromatic structures of the obtained compounds 3a–h, 4a–f, and 6a–d were proved by their IR, mass, and ^1^H‐NMR spectra.