| | 1 | Author
| Georg Ziegler3, Erwin Haug3, Wolfgang Freyb, Willi Kantlehner3 | Requires cookie* | | | Title
| Orthoamide, LVII [1]. Lassen sich aromatische Aldehyde nach Fries aus Arylformiaten hersteilen? Orthoamides, LVII [1]. Can Aromatic Aldehydes be Prepared from Aryl Formates via the Fries Rearrangement?  | | | | Abstract
| The aromatic hydroxyaldehydes 3a-3g, 5a-5f, 8 , 10 can be prepared by the action of BC13, BBr3 or trifluoromethanesulfonic acid, on the aryl formates la-lf, 4a-e, 7, 9 via Fries rear rangement. BBr3 is more effective than BC13. The activating ability of BBr3 can be improved by addition of FeCl3. Rearrangements which are induced by trifluoromethanesulfonic acid can give rise to the formations of regioisomers, which might be different from the products formed when the reaction is performed with Lewis acids. The yields of the aldehydes are lowered by subsequent condensation reactions. This view was confirmed by the isolation of a con densation product, which was characterized as a dibenzo[a,y']xanthene derivative 6 by crystal structure analysis. For the Fries rearrangement of formyl groups a new mechanism is proposed. 2-Hydroxy-1-naphthaldehyde 5c can be obtained in good yield from formic acid, BBr3, and 2 -naphthol. | | | |
Reference
| Z. Naturforsch. 56b, 1178—1187 (2001); eingegangen am 13. Juli 2001 | | | |
Published
| 2001 | | | |
Keywords
| Aromatic Hydroxyaldehydes, Fries Rearrangement, Formylation | | | |
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| default:Reihe_B/56/ZNB-2001-56b-1178.pdf | | | | Identifier
| ZNB-2001-56b-1178 | | | | Volume
| 56 | |
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