Synthesis of tetra- and octahydroxanthene derivatives by the condensation of dimedone with aromatic aldehydes

Пырко, А. Н.

doi:10.1007/bf01164861

Cited by 8 publications

(4 citation statements)

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“…E68, o1606 [doi:10.1107/S1600536812018934] 9-(2-Hydroxy-4,4-dimethyl-6-oxocyclohex-1-en-1-yl)-3,3-dimethyl-2,3,4,9-tetrahydro-1H-xanthen-1-one Dimedone condenses with an aromatic aldehyde such an salicylaldehyde to yield aldimedone, the reaction often being used as a method for characterizing aromatic aldehydes. Aldimedone is then dehydrated to the title compound C 23 H 26 O 4 (Scheme I), which features a pyran ring (Pyrko, 1996). The cyclohexene ring that constitutes a part of the tetrahydroxanthene fused-ring system has a flattened half-chair conformation that approximates an envelope conformation (in which the methylene C atom bearing the dimethyl substituent represents the flap) as five of the six atoms lie on a plane (Fig.…”

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confidence: 99%

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9-(2-Hydroxy-4,4-dimethyl-6-oxocyclohex-1-en-1-yl)-3,3-dimethyl-2,3,4,9-tetrahydro-1H-xanthen-1-one

Курбанова¹,

Gurbanov²,

Mahmudov³

et al. 2012

Acta Cryst E

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The cyclohexene ring that constitutes a part of the tetrahydroxanthene fused-ring system of the title compound, C23H26O4, adopts a flattened half-chair conformation that approximates an envelope conformation (in which the methylene C atom bearing the two methyl substituents represents the flap) as five of the six atoms lie approximately on a plane (r.m.s. deviation = 0.020 Å). The mean plane of the cyclohexene ring with the hydroxy substituent is approximately perpendicular to the mean plane of the tetrahydroxanthene system. In the crystal, adjacent molecules are linked by O—H⋯Ocarbonyl hydrogen bonds into a chain running along the b axis.

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Section: Supporting Informationmentioning

confidence: 99%

“…The compound was synthesized by using a literature method (Pyrko, 1996) and ethanol was used as the recrystallization solvent.…”

Section: S2 Experimentalmentioning

confidence: 99%

9-(2-Hydroxy-4,4-dimethyl-6-oxocyclohex-1-en-1-yl)-3,3-dimethyl-2,3,4,9-tetrahydro-1H-xanthen-1-one

Курбанова¹,

Gurbanov²,

Mahmudov³

et al. 2012

Acta Cryst E

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“…The condensation of two molecules of 1,3-cyclohexanediones with aromatic aldehydes usually produces 9-substituted octahydroxanthene [14][15][16] and tetrahydroxanthene derivatives with 2-hydroxyaromatic aldehydes [17]. The reaction mechanism involves the condensation of Knoevenagel of the molecule of cy-clohexanedione with aldehyde and subsequent Michael addition of the second molecule to formed α, βunsaturated diketone.…”

Section: Introductionmentioning

confidence: 99%

Synthesis of 4-(2-Hydroxyphenyl)-5,6,7,8-Tetrahydroisoxazolo [5,4-B]chromene-5(4h)-Ones

Pyrko¹

2018

IVUZKKT

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The aim of this work is the synthesis of new tetraheterocyclic compounds of interest as potential biologically active substances that include the isoxazole and chromone moieties in their structure. The synthesis of such compounds was carried out with two stages. By Knoevenagel condensation of 3-methyl-1,2-isoxazol-5(2H)-on with salicylic aldehyde (4Z)-4-(2-hydro-xybenzyliden)-3-methyl-1,2-oxazol-5(4H)-on was obtained. In this reaction an excess of half of the aldehyde equivalent was used to increase the yield of the product. Pyperidine was used as a catalyst. The reaction was carried out by boiling the components in ethyl acetate. The reaction of the resulting benzylidenisoxazole derivative with cyclohexane-1,3-dione or dimedone was performed by boiling the components in ethanol without the use of a catalyst. The interaction mechanism includes heterodiene Dielsa-Aldera condensation followed by dehydration of one water molecule. As a result, 3-methyl-4-(2-hydroxyphenyl-5,6,7,8-tetrahydroisoxazolo[5,4-b]chromene-5(4H)-one and 3,7,7-trimethyl-4-(2-hydroxyphenyl)-5,6,7,8,9-tetrahydroisoxazolo[5,4-b]chromen-5(4H)–one were obtained. Purification of the synthesized compounds was carried out by crystallization from ethanol. All the obtained compounds were characterised by IR 1H NMR and UV spectroscopies. In 1H NMR spectra there are signals of the methyl groups of the isoxazole ring of compounds at 2.26, 2.29, 2.34 ppm respectively. In the UV spectrum of a plane molecule of (4Z)-4-(2-hydroxybenzyliden)-3-methyl-1,2-oxazol-5(4H)-on there is a long-wave absorption maximum (400.9 nm) corresponding to the joint system of conjugated bonds of the isoxazole and aromatic rings. The structures of the obtained compounds were confirmed by high resolution mass-spectrometry analysis. In the spectra of 3-methyl-4-(2-hydroxyphenyl-5,6,7,8-tetrahydroisoxazolo[5,4-b]chromene-5(4H)-one and 3,7,7-trimethyl-4-(2-hydroxyphenyl)-5,6,7,8,9-tetrahydroisoxazolo[5,4-b]chromen-5(4H)–one the[M + Na]+ ion peaks were observed. The presence of fragment peaks [M + Na – CO]+ and [M + Na – CO – H2O]+ confirms the presence of hydroxy and carbonyl groups in the molecules.

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“…Apart from the presence of conjugated and nonconjugated 1,3 and 1,5 carbonyl groups, it is distinguished by the presence of a tetrahydroxanthene fragment, which affects the reactivity, for example, to ward nucleophilic reactions with amines. 3 Since the molecule of triketone 1 has several reaction centers, we carried out quantum chemical prediction of the most likely site of electrophilic addition of bromine taking into account the first step of bromination, i.e., enolization of one of the carbonyl functions. 4, 5 According to quantum chemical calculations, the for mation of enol 1B is thermodynamically most favorable (Table 1).…”

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confidence: 99%

Bromination of 9-dimedonyltetrahydroxanthenone as a route to a new type of substituted hydrochromeno[2,3,4-kl]xanthenones

Nikishin

Федотова

2007

Russ Chem Bull

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Bromination of 9 dimedonyl 3,3 dimethyl 2,3,4,9 tetrahydro 1H xanthen 1 one was car ried out to provide a route to a new series of substituted hydrochromeno[2,3,4 kl]xanthenones, which may find application for the synthesis of poorly accessible compounds including the heteroanalogs. A dependence of transformations of dimedonyltetrahydroxanthenone on the nature of the solvent was elucidated: bromination at the α methylene groups of the dimedonyl substituent is accompanied by heterocyclization involving 1 and 5 oxo groups. Quantum chemical HF/6 311(d,p) ab initio calculations for the proposed mechanism of hemiacetalization and halogenation were carried out.

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Synthesis of tetra- and octahydroxanthene derivatives by the condensation of dimedone with aromatic aldehydes

Cited by 8 publications

References 1 publication

9-(2-Hydroxy-4,4-dimethyl-6-oxocyclohex-1-en-1-yl)-3,3-dimethyl-2,3,4,9-tetrahydro-1H-xanthen-1-one

9-(2-Hydroxy-4,4-dimethyl-6-oxocyclohex-1-en-1-yl)-3,3-dimethyl-2,3,4,9-tetrahydro-1H-xanthen-1-one

Synthesis of 4-(2-Hydroxyphenyl)-5,6,7,8-Tetrahydroisoxazolo [5,4-B]chromene-5(4h)-Ones

Bromination of 9-dimedonyltetrahydroxanthenone as a route to a new type of substituted hydrochromeno[2,3,4-kl]xanthenones

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