- Preparation and stereochemistry of the isopropylidene derivatives of 1,2-dihydronaphtho[2,1-b]furan-1,2-diol and 1,2,9,10-tetrahydronaphtho[2,1-b:7, 8-b′] difuran-1,2,9,10-tetraol in comparison with the corresponding acetyl derivatives
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1,2-Dihydronaphtho[2,1-b]furan-1,2-diol and 1,2,9,10-tetrahydronaphtho[2,1- b:7,8-b′]difuran-1,2,9,10-tetraol were transformed into the corresponding isopropylidene derivatives, which were studied mainly by 1H NMR and chiral HPLC analyses in terms of a possible transformation mechanism and stereochemistry in comparison with their corresponding acetyl derivatives.
- Yamaye, Makoto,Motoyanagi, Yoshiko,Nakagawa, Aya,Kametani, Sanae,Yoshinaga, Tetsutaro,Cho, Namiko,Fan, Xiaobo,Kito, Taketoshi
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- Pd(OAc)2-catalyzed lactonization of arylacetamides involving oxidation of C-H bonds
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The reaction of arylacetamides that contain a quinolin-8-ylmethylamine as the directing group with PhI(OAc)2, in the presence of Pd(OAc)2 as the catalyst, results in lactonization to give γ-lactones, the formation of which involves activation of the ortho C-H bonds, with concomitant cleavage of the directing group.
- Uemura, Takeshi,Igarashi, Takuya,Noguchi, Moe,Shibata, Kaname,Chatani, Naoto
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supporting information
p. 621 - 623
(2015/05/20)
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- Metal-free oxidative cyclization of alkynyl aryl ethers to benzofuranones
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Readily available phenols can be converted into substituted aryl alkynyl ethers, which react with an N-oxide as an oxidant and catalytic amounts of a Bronsted acid to provide benzofuranones. If non-terminal alkynyl ethers are applied, a 1,2-hydride shift takes place and phenyl acrylates are obtained. Thus activated alkynes can serve as α-oxy carbene precursors even in the absence of a metal catalyst. Copyright
- Graf, Katharina,Ruehl, Carmen L.,Rudolph, Matthias,Rominger, Frank,Hashmi, A. Stephen K.
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p. 12727 - 12731
(2013/12/04)
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- 2-(2-Hydroxyaryl)cinnamic amides: a new class of axially chiral molecules
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The syntheses of several differently substituted amides formally derived from a chiral amine, either E-2-(2-hydroxyphenyl)cinnamic acid or both E- and Z-2-(2-hydroxynaphthyl)cinnamic acid, are reported. These molecules display a restricted rotation about
- Marelli, Chiara,Monti, Chiara,Galli, Simona,Masciocchi, Norberto,Piarulli, Umberto
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p. 8943 - 8951
(2007/10/03)
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- Anionic Homologous Fries Rearrangement of O-(2-Methylaryl)carbamates. A Regiospecific Route to Benzo[b]furan-2(3H)-ones including an Unnamed Metabolite from Helenium Species
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A new LDA mediated O → C carbamoyl migration, 3 provides a general and efficient route to aryl acetamides 5, precursors to the benzo- and naphthofuranones 7, one of which serves as a starting material for a short synthesis of naturally-occurring benzofuranolactol 11 isolated from several Helenium species.
- Kalinin,Miah,Chattopadhyay,Tsukazaki,Wicki,Nguen,Coelho,Kerr,Snieckus
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p. 839 - 841
(2007/10/03)
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- Photodegradation of Dichlorprop and 2-Naphthoxyacetic Acid in Water. Combined GC-MS and GC-FTIR Study
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We have examined the photochemical transformations of dichlorprop (1) and 2-naphthoxyacetic acid (2) in aqueous solution, by means of combined GC-MS and GC-FTIR analysis. Photolysis of 1 under oxygen atmosphere led to 2-chlorophenol (5), 2,4-dichlorophenol (6), 4-chlorophenol (7), 2,4-dichlorophenyl acetate (8), the lactone of 2-(4-chloro-2-hydroxyphenoxy)propionic acid (9), and 2-(2-chlorophenoxy)propionic acid (10). Irradiation under argon atmosphere led again to 5, 6, 7, and 10 together with 2,4-dichlorophenyl ethyl ether (11). Photolysis of 2 under aerobic conditions gave β-naphthol (12), together with minor amounts of 2-hydroxy-1-naphthaldehyde (13) and naphtho [2,1-b]furan-2(1H)-one (14). Under argon atmosphere only 12 and 14 were detected. Therefore, the most general processes were photolytic cleavage of the aryl-halogen bond (route i) and the aryloxy-carbon bond (route ii). Similar photodegradation pathways had been previously observed for 2,4-D and 4-CPA and were confirmed in this work. The formation of 8, 11, and 13 must occur via cleavage of the carbon-carbon bond a to the carboxy group (route iii). Formation of this type of photoproducts in phenoxyalkanoic acid pesticides is unprecedented. Its structure was further assessed by alternative synthesis.
- Climent, Maria Jose,Miranda, Miguel A.
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p. 1916 - 1919
(2007/10/03)
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- Base-Catalyzed Alkylation of 2-Naphthol with Glyoxal
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Alkylation of potassium 2-naphthyl oxide with glyoxal in aqueous media formed 1,2-dihydronaphthofuran-1,2-diol (1).Without isolation of 1, acidification of this reaction mixture with aqueous HCl led to three products, i.e., the lactone of (2-hydroxy-1-naphthyl)acetic acid (2), the hemiacetal of bis(2-hydroxy-1-naphthyl)acetaldehyde (3), and the corresponding acetal (4).Mutual interconversions of 1 and these three products revealed the reaction pathway and the mechanisms of formation of the lactone and the acetal.
- Kito, Taketoshi,Yoshinaga, Kohji,Yamaya, Makoto,Mizobe, Hoyou
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p. 3336 - 3339
(2007/10/02)
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