X-ray structural analysis of 4-bromo-2,2-dimethyl-5-oxy-6,6,7,7,8,8,9,9,9-nonafluorononan-3-one

The features of the molecular and crystal structures of 4-bromo-2,2-dimethyl-5-oxy-6,6,7,7,8,8,9,9,9-nonafluorononan-3-one are determined by XRD.     

Reactions of 2,2-dimethyl-3-phenylazirine with hydrazine and its derivatives

The corresponding -amino ketone hydrazones were obtained by reaction of 2,2-dimethyl-3-phenylazirine with hydrazine, N,N-dimethylhydrazine, methylhydrazine, and semicarbazide. It was established that unsymmetrical azines are formed in the reaction of 2-amino-2-methyl-1-phenyl-1-propanone hydrazone with aliphatic and cyclic ketones. The corresponding tetrahydro-1,2,4-triazines were obtained in the case of the analogous reaction with aliphatic and aromatic aldehydes.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 3, pp. 342–346, March, 1978.     

Reactions of 2,2-dimethyl-3-phenylazirine with hydrazino and amino alcohols

The reaction of 2,2-dimethyl-3-phenylazirine with -hydrazino alcohols leads to the corresponding -hydroxyalkylhydrazones of 2-amino-2-methyl-1-phenyl-1-propanone. The reaction of the same azirine with - and -amino alcohols gives primarily substituted oxazolidines and perhydro-1,3-oxazine, respectively, which undergo isomerization to the chain form, viz., the corresponding N-(2-amino-2-methyl-1-phenylpropylidene)amino alcohols; the tendency to undergo isomerization to the chain form is not manifested in the case of -aminoethanol. A conclusion regarding the preferred conformation of the oxazolidines was drawn on the basis of the data from ¹H and ¹³C NMR spectroscopy. The product of the reaction of azirine with -aminoethanol is 2,5,5-trimethyl-4-phenyl-3-imidazoline.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 10, pp. 1363–1367, October, 1981.     

Reaction of methyl 1-(2-bromo-4-methoxy-1,4-dioxobutyl)- cyclohexanecarboxylate with zinc and aromatic aldehydes

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Reactions of regioisomeric 3,3-dimethyl- and 2,2-dimethyl-6-trifluoromethyl-2,3-dihydro-4-pyrones with N-nucleophiles

Reactions of 2,2-dimethyl-6-trifluoromethyl-2,3-dihydro-4-pyrone with ethylenediamine, hydrazine, or hydroxylamine yield 5-methyl-7-trifluoromethyl-2,3-dihydro-1H-1,4-diazepine, 3(5)-(2-hydroxy-2-methylpropyl)-5(3)-trifluoromethylpyrazole, and 5-hydroxy-3-(2-hydroxy-2-methylpropyl)-5-triflouromethyl-Δ², respectively. The same compounds were obtained from 2-amino-1,1,1-trifluoro-6-hydroxy-6-methylhept-2(Z)-en-4-one and 2-hydroxy-6, 6-dimethyl-2-trifluoromethyltetrahydro-4-pyrone.     

Reaction of ethyl 2,4-dibromo-2,4-dimethyl-3-oxopentanoate with zinc and aldehydes

Ethyl 2,4-dibromo-2,4-dimethyl-3-oxopentanoate reacts with zinc and aliphatic or aromatic aldehydes to furnish 3,5,5-trimethyl-6-R-2,3,5,6-tetrahydropyran-2,4-diones as a single geometrical isomer that in polar solvents converts into enol form.     

Reactions of 2,2-dimethyl-3-phenylazirine with chlorides of unsaturated and amino-substituted acids

The reaction of 2,2-dimethyl-3-phenylazirine with N-phthalylglycine acid chloride gives initially N-acyl-3-chloroaziridine, which undergoes isomerization to a substituted 2-oxazoline and the corresponding keto amide. The reaction of 2,2-di-methyl-3-phenylazirine with the chlorides of crotonic, - (2-furyl) acrylic, cinnamic, and phenylpropiolic acids in benzene at 20 °C leads to 2,2-dimethylindoxyl and the corresponding unsaturated acid.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 5, pp. 643–645, May, 1981.     

6-quinolinylamine condensation with aldehydes and methyl 2,2-dimethyl-4,6-dioxocyclohexanecarboxylate

A condensation of methyl 2,2-dimethyl-4,6-dioxocyclohexanecarboxylate with 6-quinolinylamine and aldehydes of aromatic (heteroaromatic, alicyclic) series gave rise to new derivatives of 4,7-phenanthroline. The condensation in ethanol proceeded regioselectively and with a high extent of stereoselectivity leading to the formation of a mixture of cis- and trans- methyl 9,9-dimethyl-12-aryl (heteryl, cyclohexenyl)-11-oxo-7,8,9,10,11,12-hexahydrobenzo[b]-4,7-phenanthroline-10-carboxylates. In the more severe conditions both regio- and stereoselectivity of the process decreased resulting in the formation of a mixture of 8- and 10-methoxycarbonyl derivatives (∼1:2), and somewhat grew the fraction of the cis-isomers in the mixture.     

无外加催化剂条件下邻取代芳香醛与5, 5-二甲基-1, 3-环己二 酮的反应研究

在DMF溶剂中,不外加催化剂使邻取代芳香醛(1)与5,5-二甲基-1,3-环己二酮(2)发生缩合和加成反应生成3,3,6,6-四甲基-4a-羟基-9-芳基-1,8-二氧代-2,3,4,4a,5,6,7,8,9,9a-十氢化-1H-氧杂蒽(3a-3d)。在同样条件下,邻羟基芳香醛与5,5-二甲基-1,3-环己二酮则发生缩合、加成和脱水反应生成3,3-二甲基-9-(5,5-二甲基-3-羟基-2-环己烯-1-酮-2-基)-1-氧代-2,3,4,9-四氢化-1-氧杂蒽(4a-4b)。用单晶X-射线分析法确定了产物3a和4a的晶体结构。     

Direct preparation of 3,4-dichloro-2,-dimethyl-3-chromenes from 2,2-dimethyl-4-chromanones

Reaction of 2,2-dimethyl-4-chromanones($\text{1}$) with two equivalents of phosphorus pentachloride affords, 3,4-dichloro-2,2-dimethyl-3-chromenes($\text{2}$) in variable yields depending on the substituents of the aromatic ring. A plausible pathway for this reaction is given.     

Preparation of 2,2'-dihydroxytriphenylmethanes using metal phenolates with aromatic aldehydes

The reactions of oxophilic metal phenolates having electron-donating substituents (1a-c) with aromatic aldehydes (2, 3) were selectively condensed at the ortho-position of the starting phenol to afford 2,2'-dihydroxytriphenylmethanes (8-11). This method was also applicable to the preparation of bisphenols (12-17) starting with naphthaldehydes (4, 5) and pyridinecarboxaldehydes (6, 7), but in low yields. In the case of these aldehydes (4-7), satisfactory yields could be obtained by sonication.     

Reactions of organozinc reagents derived from dialkyl 2,2-dibromomalonates with 3-aryl-2-cyanoprop-2-enamides

Organozinc compounds obtained by treatment of dialkyl 2,2-dibromomalonates with metallic zinc reacted with N-substituted 3-aryl-2-cyanoprop-2-enoic acid amides to give alkyl 3-R-6-aryl-5-cyano-2,4-dioxo-3-azabicyclo[3.1.0]hexane-1-carboxamides as a single stereoisomer.     

Reactions of 3-hydroxy-1,2-dihydroquinazolin-4-ones with aldehydes

The reactions of 3-hydroxy-2-(2-hydroxyalkyl)- [or (2-hydroxyaryl)]-1,2-dihydro-quinazolin-4-ones with formaldehyde or acetaldehyde afford 1,3-oxazino[3,4-a]quinazolin-4-one derivatives. The reactions with other aldehydes RCHO and 3-hydroxy-2-R′-1,2-dihydroquinazolin-4-ones can give 3-hydroxy-2-R-1,2-dihydroquinazolin-4-ones, 2-substituted quinazolin-4-ones, or dianthranilide. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 12, pp. 2523–2526, December, 1998.     

Effective 1,5-, 1,6- and 1,7-remote stereocontrol in reactions of alkoxy- and hydroxy-substituted allylstannanes with aldehydes

Alk-2-enylstannanes with 4-, 5- and 6-alkoxy- or -hydroxy-substituents are transmetallated stereoselectively with tin(iv) halides to generate allyltin trihalides which react with aldehydes to give (Z)-alk-3-enols with useful levels of 1,5-, 1,6- and 1,7-stereocontrol. Alk-2-enylstannanes with a stereogenic centre bearing a hydroxy or alkoxy group at the 4-, 5- or 6-position, react with overall (Z)-1,5-, 1,6- and 1,7-syn-stereoselectivity with respect to the hydroxy and alkoxy substituents. The analogous reactions of alkoxy- and -hydroxyalk-2-enylstannanes with a methyl bearing stereogenic centre at the 4- or 5-position react with overall (Z)-1,5- and 1,6-anti-stereoselectivity with respect to the hydroxy and methyl substituents.     

Reactions of aromatic aldehydes and their acetals with phosphorous acid esters

Russian Journal of General Chemistry -     

Reaction of alkyl 5,5-dimethyl-2-oxo-2,5-dihydrofuran-3-carboxylates with zinc enolates prepared from zinc and 1-arul-2-bromo-2-phenylethanones, 2 bromoindanone, and 2-bromo-6-methyltetralone

Alkyl 5,5-dimethyl-2-oxo-2,5-dihydrofuran-3-carboxylates react with zinc enolates prepared from 1-aryl-2-bromo-2-phenylethanones, 2-bromo indanone, 2-bromo-6-methyltetralone and zinc with formation of ethyl 4-(2-aryl-2-oxo-1-phenyl-ethyl)-5,5-dimethyl-2-oxotetrahydrofuran-3-carboxylates, alkyl 5,5-dimethyl-2-oxo-4-(1-oxoindan-2-yl)tetrahydrofuran-3-carboxylates, and ethyl 5,5-dimethyl-4-(6-methyl-1-oxo-1,2,3,4-tetrahydronaphthalen-2-yl)-2-oxotetrahydrofuran-3-carboxylates respectively, mainly as single diastereomers.     

The regioselectivity of rhodium and palladium-catalysed cyclisations of 2-bromo-1,6- and -1,7-dienes

2-Bromo-l,6-dienes are catalytically cyclised to a mixture of the corresponding 3,4-bis(methylene)cyclopentane and 5-methylenecyclohex-3-ene. Wilkinson's catalyst shows good selectivity for the 5-membered ring product whilst palladium catalysts, in general, show little selectivity, Addition of tetraethylammonium salts, especially the chloride, allow the palladium catalysed reactions to be carried out at 30°C in good yield and with high selectivity for the 5-membered ring. 2-Bromo-1,7-dienes are cyclised regio-specifically to 6-membered rings by the same catalysts although some double bond isomerisation also occurs. The mechanism of the catalytic cyclisations is discussed. The 3,4-bis(methylene) cyclopentanes undergo facile Diels-Alder reactions.