A Wittig-olefination–Claisen-rearrangement approach to the 3-methylquinoline-4-carbaldehyde synthesis
| Autor: | Yunnus B. Shaikh, Mukund G. Kulkarni, Ajit N Dhatrak, Ramesh Gannimani, Deekshaputra R. Birhade, Mayur P. Desai |
|---|---|
| Jazyk: | angličtina |
| Rok vydání: | 2012 |
| Předmět: |
chemistry.chemical_classification
Olefin fiber acetal Xylene Acetal Organic Chemistry Claisen rearrangement ring-closure Aldehyde Full Research Paper oxidative cleavage lcsh:QD241-441 Crotyl chemistry.chemical_compound Chemistry lcsh:Organic chemistry chemistry Wittig reaction Organic chemistry lcsh:Q Wittig olefination lcsh:Science Oxidative cleavage |
| Zdroj: | Beilstein Journal of Organic Chemistry Beilstein Journal of Organic Chemistry, Vol 8, Iss 1, Pp 1725-1729 (2012) |
| ISSN: | 1860-5397 |
| Popis: | Efficient syntheses are described for the synthetically important 3-methylquinoline-4-carbaldehydes 6a–h from o-nitrobenzaldehydes 1a–h employing a Wittig-olefination–Claisen-rearrangement protocol. The Wittig reaction of o-nitrobenzaldehydes with crotyloxymethylene triphenylphosphorane afforded crotyl vinyl ethers 2a–h, which on heating under reflux in xylene underwent Claisen rearrangement to give 4-pentenals 3a–h. Protection of the aldehyde group of the 4-pentenals as acetals 4a–h and subsequent oxidative cleavage of the terminal olefin furnished nitroaldehydes 5a–h. Reductive cyclization of these nitroaldehydes yielded the required 3-methylquinoline-4-carbaldehydes 6a–h in excellent yields. Therefore, an efficient method was developed for the preparation of 3-methylquinoline-4-carbaldehydes from o-nitrobenzaldehydes in a simple five-step procedure. |
| Databáze: | OpenAIRE |
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