Synthesis of 1-substituted 2-azaspiro[4.5]deca-6,9-dien-8-ones and 2-azaspiro[4.5]deca-1,6,9-trien-8-ones by condensation of 2,6-dimethylphenol with isobutyraldehyde and nitriles

1-Substituted 3,3,7,9-tetramethyl-2-azaspiro[4.5]deca-6,9-dien-8-ones and 3,3,7,9-tetramethyl-2-azaspiro[4.5]deca-1,6,9-trien-8-ones were synthesized by three-component condensation of 2,6-dimethylphenol with isobutyraldehyde and nitriles in concentrated sulfuric acid.     

Spirocyclohexadienones. 6. Three-component synthesis of 1-R-3,3-dimethyl-2-azaspiro[4.5]deca-1,6,9-trien-8-ones

1-R-3,3-Dimethyl-2-azaspiro[4.5]deca-1,6,9-trien-8-ones were synthesized through three-component condensation of anisole, isobutyraldehyde, and a corresponding nitrile in dichloromethane in the presence of concentrated sulfuric acid.     

A simple and efficient route for the synthesis of novel isoxazolyl-2-azaspiro[4.5]deca-1,6,9-trien-8-ones

A new, simple and efficient method for the synthesis of novel isoxazolyl-2-azaspiro[4.5]deca-1,6,9-trien-8-ones is described by the intramolecular ipso-cyclization of 5-[(E)-2-(4-methoxyphenyl)-1-ethenyl]-3-methyl-4-nitroisoxazole with nitriles. In presence of 5-[(E)-2-(4-methoxyphenyl)-1-ethenyl]-3-methyl-4-nitroisoxazole, a variety of nitriles underwent the intramolecular ipso-cyclization smoothly, affording title compounds in moderate to good yields.     

Synthesis of 1-substituted (R,S)-8-(2-methoxy-5-methylphenyl)-3,3,9-trimethyl-2-azaspiro[4.5]deca-1,7-dien-6-ones

Reactions between p-methylanisole, isobutyraldehyde, and nitriles (acetonitrile, methyl thiocyanate, or ethyl cyanoacetate) in conc. H₂SO₄ yield 1-substituted (R,S)-8-(2-methoxy-5-methylphenyl)-3,3,9-trimethyl-2-azaspiro[4.5]deca-1,7-dien-6-ones.     

Spirocyclohexadienones. 4. Synthesis and dienone-phenolic rearrangement of 1-R-3,3-dialkyl-2-azaspiro[4.5]deca-1,6,9-trien-8-ones

The reactions of 1-(p-methoxyphenyl)-2-methylpropan-1-ol or -cyclohexyl-p-methoxybenzyl alcohol with nitriles RCN in concentrated sulfuric acid afforded 1-R-3,3-dialkyl-2-azaspiro[4.5]deca-1,6,9-trien-8-ones. The stability of the latter toward the dienone-phenolic rearrangement depends on the nature of the substituent R. The reaction mechanism was studied by the semiempirical quantum-chemical AM1 method.     

Ritter reaction. Synthesis of 1-substituted 3,3,7,9-tetramethyl-2-azaspiro[4.5]deca-6,9-dien- and -1,6,9-trien-8-ones and 7-methoxy-3,3,6,8-tetramethyl-3,4-dihydroisoquinolines

1-(4-Methoxy-3,5-dimethylphenyl)-2-methylpropan-1-ol reacted with nitriles [MeSCN, PhCN, MeCN, EtOC(O)CH₂CN] in the presence of concentrated sulfuric acid to give both 1-R-3,3,7,9-tetramethyl-2-azaspiro[4,5]deca-6,9-dien- and -1,6,9-trien-8-ones and 1-R-7-methoxy-3,3,6,8-tetramethyl-3,4-dihydroisoquinolines. The reaction with 3,4-dimethoxyphenylacetonitrile afforded 10,11-dimethoxy-1,3,6,6-tetramethyl-1,5,6,12b-tetrahydrodibenzo[d,f]indole-2,8-dione. Three-component condensation of 2-methoxy-1,3-dimethylbenzene with isobutyraldehyde and nitriles led to the formation of spirocyclic systems and 3,4-dihydroisoquinoline derivatives in lower yield.     

Spirocyclohexadienones. 7. Three-component condensation of 1- or 2-methoxynaphthalene with isobutyraldehyde and nitriles

1-R-3,3-Dimethylbenzo[i]-2-azaspiro[4.5]deca-1,6-dien-8-ones or 1-R-3,3-dimethylbenzo[i]-2-azaspiro[4.5]deca-1,7-dien-6-ones were synthesized by three-component condensation of 1- or 2-methoxynaphthalene, isobutyraldehyde (or isobutylene oxide), and nitrile RCN in concentrated sulfuric acid.     

7-(羟甲基)-8-氮杂螺[4.5]癸烷-8-羧酸叔丁酯的合成

以8-氮杂螺[4.5]癸烷-7,9-二酮为原料,通过酰胺还原、N-Boc保护、甲酰化、醛基四步反应还原反应合成得到目标化合物7-(羟甲基)-8-氮杂螺[4.5]癸烷-8-羧酸叔丁酯,总收率29.8％.反应中间体及产物结构经1 H NMR和ESI-MS确证,同时对每步反应条件进行讨论.该研究提供了一种新结构的含氮螺环化合...     

Spirocyclohexadienones: IX. Synthesis of 1-alkoxycarbonylmethylidene-6,10-dimethoxy-8-[(alkoxycarbonyl)cyanomethylidene]-3,3-R<Subscript>2</Subscript>-2-azaspiro[4.5]deca-6,9-dienes by four-component condensation of 1,3,5-trimethoxybenzene with α-branched aldehydes and alkyl cyanoacetates

Four-component condensation of 1,3,5-trimethoxybenzene, a C₂-synton, and alkyl cyanoacetate in the presence of concentrated sulfuric acid gave the corresponding 1-alkoxycarbonylmethylidene-6,10-dimethoxy-8-[(alkoxycarbonyl)cyanomethylidene]-3,3-R₂-2-azaspiro[4.5]deca-6,9-dienes.     

Synthesis of fluorine-containing 1,4-dioxa-2-azaspiro-[4.5]deca-2,6,9-trienes by reaction of polyfluorinated cyclohexa-2,5-dienones with nitrile oxides

4-Pentafluorophenoxy-, 4-nitro-, and 4-chloropentafluorocyclohexa-2,5-dien-1-ones and 3,4,5-tris-(pentafluorophenoxy)trifluorocyclohexa-2,5-dien-1-one react with some benzonitrile and acetonitrile oxides exclusively at the carbonyl group, leading to the formation of mixtures of diastereoisomeric fluorinated 1,4-dioxa-2-azaspiro[4.5]deca-2,6,9-trienes in good yield.     

Synthesis of 8-oxa-2-azaspiro[4.5]decane

A convenient synthesis of new 8-oxa-2-azaspiro[4.5]decane from commercially available reagents based on tetrahydropyran-4-carbonitrile and 1-bromo-2-fluoroethane has been developed. This compound is promising for the production of important biologically active compounds.

     

Enantioselective microbial reduction of 6-oxo-8-[4-[4-(2-pyrimidinyl)-1-piperazinyl]butyl]-8-azaspiro[4.5]decane-7,9-dione

The enantioselective microbial reduction of 6-oxo-8-[4-[4-(2-pyrimidinyl)-1-piperazinyl]butyl]-8-azaspiro[4.5]decane-7,9-dione 1 to either of the corresponding (R)- or (S)-6-hydroxy-8-[4-[4-(2-pyrimidinyl)-1-piperazinyl]butyl]-8-azaspiro[4.5]decane-7,9-diones 2 and 3 is described.     

Five-Membered 2,3-dioxoheterocycles: XCV. Recyclization of 4-benzoyl-5-phenylfuran-2,3-dione at the action of substituted 1,3,3-trimethyl-2-azaspiro[4.5]dec-1-enes. Crystal and molecular structure of substituted 5-(2-azaspiro[4.5]dec-1-ylidene)cyclopent-3-ene-1,2-dione

4-Benzoyl-5-phenylfuran-2,3-dione reacts with 2′,5′,5′-trimethyl-4′,5′-dihydro-4H-spiro[naphthalene-1,3′-pyrrol]-4-one and 8-(2-methoxy-5-methylphenyl)-1,3,3,9-tetramethyl-2-azaspiro[4.5]deca-1,7-dien-6-one with the formation of (Z)-3-benzoyl-5-(5′,5′-dimethyl-4-oxo-4H-spiro[naphthalene-1,3′-pyrrolidin]-2′-ylidene)-4-phenylcyclopent-3-ene-1,2-dione, whose structure was proved by XRD analysis, and of (Z)-3-benzoyl-5-{8-(2-methoxy-5-methylphenyl)-3,3,9-trimethyl-6-oxo-2-azaspiro[4.5]dec-7-en-1-ylidene}-4-phenylcyclopent-3-ene-1,2-dione.     

Design,Synthesis, and Antitumor Activity of a Series of Novel 4-(Aromatic Sulfonyl)-1-oxa-4-azaspiro[4.5]deca-6,9-dien-8-ones

Many sulfonamides show anticancer activity. Based on benzenesulfonylazaspirodienone (HL-X9) identified in our previous work, we optimized the lead compound for better efficacy, thereby synthesizing a series of novel 4-(aromatic sulfonyl)-1-oxa-4-azaspiro[4.5]deca-6,9-dien-8-one derivatives through a key step of metal-catalyzed cascade cyclization. The preliminary antiproliferative tests have shown that the anticancer activities of acetyl-protected mannose-linked sulfonylazaspirodienone derivatives (7i–7l) have been greatly improved. Among them, 7j is the most potent derivative, with IC₅₀ values of 0.17 µM, 0.05 µM, and 0.07 µM for A549, MDA-MB-231, and HeLa cell lines, respectively. Flow cytometry analysis shows that 7j arrests MDA-MB-231 cells in the G2/M phase and has a certain effect on the apoptosis of MDA-MB-231 cells. In addition, the acute toxicity of 7j was lower than that of adriamycin.     

Synthese des 6- und 7-Methyl-spiro[4.5]deca-6,9-dien-8-ons

Zusammenfassung Es werden die Synthesen folgender Verbindungen beschrieben: -(4-Hydroxy-3-methylphenyl)buttersäure, 4-(4-Hydroxy-3-methylphenyl)-1-butanol, 7-Methyl-spiro[4.5]deca-6,9-dien-8-on, -(4-Hydroxy-2-methylphenyl)buttersäure und dessen Methylester, 4-(4-Hydroxy-2-methylphenyl)-1-butanol und 6-Methyl-spiro[4.5]deca-6.9-dien-8-on.

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The synthesis of the following compounds is described: -(4-hydroxy-3-methylphenyl)-butyric acid, 4-(4-hydroxy-3-methylphenyl)-butanol-(1), 7-methyl-spiro[4.5]deca-6.9-dien-8-one, -(4-hydroxy-2-methylphenyl)-butyric acid and its methyl ester, 4-(4-hydroxy-2-methylphenyl)-butanol-(1) and 6-methyl-spiro[4.5]deca-6.9-dien-8-one.

     

Synthesis of enantiopure 1-azaspiro[4.5]dec-6-en-8-ones from l-proline derivatives

An enantioselective synthesis of protected 1-azaspiro[4.5]dec-6-en-8-one derivatives was achieved using an alkylidene carbene 1,5-CH insertion reaction as the key step.     

Spirocyclohexadienones: VIII. 1-R-3,3-Dimethyl-2-azaspiro[5.5]undeca-1,7,10-trien-9-ones

1-R-3,3-Dimethyl-2-azaspiro[5.5]undeca-1,7,10-trien-9-ones were synthesized by condensation of 4-(p-methoxyphenyl)-2-methylbutan-2-ol with nitriles RCN in the presence of a concn. sulfuric acid.     

Five-membered 2,3-dioxo heterocycles: XCII. Reaction of 3-aroyl-1H-pyrrolo[2,1-c][1,4]benzoxazine-1,2,4-triones with ethyl (2Z)-(3,3-dimethyl-8-oxo-2-azaspiro[4.5]deca-6,9-dien-1-ylidene)ethanoate. Synthesis of bridged analogs of pyrrolizidine alkaloids

3-Aroyl-1H-pyrrolo[2,1-c][1,4]benzoxazine-1,2,4-triones reacted with ethyl (2Z)-(3,3-dimethyl-8-oxo-2-azaspiro[4.5]deca-6,9-dien-1-ylidene)acetate to give ethyl 6′-aryl-2′-(2-hydroxyphenyl)-11′,11′-dimethyl-3′,4,4′,13′-tetraoxospiro[2,5-cyclohexadiene-1,9′-(7′-oxa-2′,12′-diazatetracyclo[6.5.1.0^1,5.0^8,12]tetradec-5′-ene)]-14′-carboxylates whose structure was confirmed by X-ray analysis. The products may be regarded as bridged analogs of pyrrolizidine alkaloids, 7′-oxa-2′,12′-diazatetracyclo[6.5.1.01,5.08,12]tetradecanes.     

Spirocyclohexadienones: X. Three-component condesation of 1,2,3- and 1,2,4-trimethoxybenzenes with cyclohexanecarbaldehyde and nitriles. Synthesis of 1,2- and 1,4-dimethoxy-14-azadispiro[5.1.5.2]pentadeca-1,4-dien-3-ones

Substituted 1,2- and 1,4-dimethoxy-14-azadispiro[5.1.5.2]pentadeca-1,4-dien-3-ones and 1,2(1,4)-dimethoxy-14-azadispiro[5.1.5.2]pentadeca-1,4,14-trien-3-ones were synthesized by three-component condensation of cyclohexanecarbaldehyde with 1,2,3- or 1,2,4-trimethoxybenzene and the corresponding nitriles in the presence of concentrated sulfuric acid.     

Five-membered 2,3-dioxoheterocycles: XCVI. Reactions of 3-aroylpyrrolo[1,2-a]quinoxaline-1,2,4(5h)-triones with substituted 1,3,3-trimethyl-2-azaspiro[4.5]dec-1-enes

3-Aroylpyrrolo[1,2-a]quinoxaline-1,2,4(5H)-triones react with 1,3,3,7,9-pentamethyl-2-azaspiro-[4.5] deca-1,6,9-trien-8-one and 2′,5′,5′-trimethyl-4′,5′-dihydro-4H-spiro[naphthalene-1,3′-pyrrol]-4-one providing 3-aroyl-2-hydroxy-3a-{(3,3,7,9-tetramethyl-8-oxo-2-azaspiro[4.5]deca-1,6,9-trien-1-yl)methyl}pyrrolo[1,2-a-quinoxaline-1,4(3a H,5H)-diones and 3-aroyl-2-hydroxy-3a-{(5′,5′-dimethyl-4-oxo-4′,5′-dihydro-4H-spiro[naphthalene-1,3′-pyrrol]-2′-yl)methyl}pyrrolo[1,2-a]-quinoxaline-1,4(3aH,5H)-diones.