Ueber Hexaoxybenzolderivate und ihre Beziehungen zur Krokonsäure und Rhodizonsäure

Nietzki, R.; Benckiser, Th.

doi:10.1002/cber.188501801110

Cited by 32 publications

(6 citation statements)

References 2 publications

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“…Finally, it must be stressed that quite a large group of molecules gathered in Table have been known for a long time. Mellitic acid (hexacarboxybenzene) and mellitates have been known since the first half of the 19th century. , The hexa iodo-, bromo-, chloro-, hexamethyl-, and hexahydroxy-benzenes (and hexahydroxylates) have also been known since the 19th century. − Hexafluorobenzene was only first synthesized in 1956, but now, it is widely used as a valuable solvent and standard in 19 F NMR. Hexaaminobenzene was first synthesized in 1929, and its crystalline state was already characterized in 1931. , Hexaphenylbenzene has been known since 1930 and hexa(trifluoromethyl)benzene, since 1960 .…”

Section: Resultsmentioning

confidence: 99%

“…Surprisingly, stable and relatively unstrained TFB candidates for the cyclohexatriene moiety, in which triply condensed moieties are fused through the six-membered ring, belong to the TFB(ii) group. Indeed, the HOMA index of the central rings in: benzothiophene (1), phenanthrene (2), hydroxyindoles (3,27), benzofuran (5), fluoroindoles (10, 27), nitroindoles (12,38), methylindole (16), benzoimidazole (18), N-methylindole (20), indole (21), diborinine (23), diaminonaphthalene (31), dihydroxynaphthalene (32), di-(dimetyloamino)naphthalene (34), difluoronaphthalene (37), dicyanonaphthalene (39), dichloronaphthalene (4), dimethylnaphthalene (41), phthalazine (42), naphthylborane (43), and naphthalene (44) TFB derivatives ranges from 0.1 to −0.1 (Table 2).…”

Section: ■ Results and Discussionmentioning

confidence: 99%

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Three Queries about the HOMA Index

Dobrowolski

2019

ACS Omega

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HOMA (Harmonic Oscillator Model of Aromaticity) is a simple, successful, and widely used geometrical aromaticity index. However, HOMA can also be used as a general molecular descriptor appropriate for any type of molecule. It reaches the global maximum for benzene, whereas the potent magnetic aromaticity NICS index has no lower or upper limits. Hence, questions arise and go beyond mere differences between the geometric and magnetic aspects of aromaticity: (1) Does a molecule of aromaticity greater than that of benzene, but undisclosed by the HOMA definition, exist? (2) Can the Kekuléne cyclohexatriene moiety with HOMA = 0 exist as a part of a larger system? (3) Can the geometrical aromaticity index be defined better? Our answer to the first query is “It is not likely enough”, to the second, “Why not define HOMA using a less mysterious molecule than cyclohexatriene?”, and to the third, “It is possible to construct another fair geometrical index, but is it better for evaluating aromaticity?” To find these answers, we have studied: (1) the HOMA and NICS indices of over 50 hexahomosubstituted benzenes, (2) the HOMA, as well as EN and GEO, indices of over 100 triply fused hexasubstituted benzenes, and (3) the HOMA and new Geometrical Auxiliary Index (GAI) , of different unsaturated and saturated, aromatic and aliphatic hydrocarbons including all alkane constitutional isomers composed of up to nine carbon atoms.

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Section: Resultsmentioning

confidence: 99%

Section: ■ Results and Discussionmentioning

confidence: 99%

Three Queries about the HOMA Index

Dobrowolski

2019

ACS Omega

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“…In addition, the investigations of Lerch (1862) and of Nietzki and Benckiser (1885) established that hexahydroxybenzene in an aqueous solution undergoes rapid autoxidation. The various products formed include both tetrahydroxyquinone and rhodizonic acid.…”

Section: Resultsmentioning

confidence: 99%

The Fermentation of Inositol by Propionibacterium Pentosaceum

Volk

Pennington

1952

J Bacteriol

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The relationship of mee8o-inositol to glucose has been a subject of interest since Fischer (1944-1945) suggested that a biological equilibrium could exist between the two. Of those authors claiming a biological synthesis of one from the other, all have used a system utilizing either animals or plants (Stetten and Stetten, 1946; Kursanov et al., 1949a, 1949b; Fernandez et al., 1944, 1945). These results have indicated that inositol could give rise to glucogenic substances or that inositol could be formed from glucogenic substances, but in no case has evidence been presented to demonstrate a direct equilibrium between inositol and glucose. Volk and Pennington (1951) demonstrated that the end products of inositol and glucose from a species of Aerobacter differed inasmuch as no 2,3-butylene glycol was formed in the fermentation of inositol. They concluded from this that glucose or the usual phosphorylated hexoses were not intermediates in the fermentation of inositol by this organism. The present work with Propionibaderium pentosaceum provides additional evidence that glucose is not an intermediate in the fermentation of inositol. METHODS The end products from the fermentation of both glucose and inositol by Propionibacterium pentosaceum, strain E.2.1.4.,8 were determined. Cells were grown in a medium consisting of the salt solution used by Volk and Pennington (1951) with the addition of 0.5 per cent yeast extract, 0.1 per cent sodium thioglycolate, 1.0 per cent glucose or inositol, and 10 per cent 0.1 M Sorensen's phosphate buffer, pH 6.8. The cells were grown for three to four days at 30 C in 2-liter Erlenmeyer flasks containing 1,500 ml of media. Cellular suspensions were prepared by centrifuging, washing once with tap water, and suspending the

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“…The suspension was filtered and the filtrate cooled; the resulting crystals were separated, washed with acetic acid, and dried over sodium hydroxide in a vacuum desiccator; wt, 0.3 g; mp 203 to 205 °C. The product was identical, in melting point and infrared spectrum, with an authentic sample of hexaacetoxybenzene [24].…”

Section: Methodsmentioning

confidence: 99%

Cyclic polyhydroxy ketones. II. xylo-trihydroxycyclohexenediolic acid and keto-inositols

Fatiadi¹,

Isbell²

1964

J. RES. NATL. BUR. STAN. SECT. A.

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A new crystalline compound, Dlrxylo-t rihydro xycycloh exenediolic acid (oL-xylo-pen ta-h yd rox y-2-cyclohexen-1-on e) (1), has been isola ted from the products of oxidation of myoinositol with nitric acid, and its structme has been establi shed. Compound (1) r educes Tillm a ns reagen t, reacts with iodin e in n eu tral or sli ghtly acidi c solution, produces a blue color with ferric chloride soluti on, and exhibits othe r properti es cha racteri stic of a n en ediolic acid. On catalyt ic reduction , it gives both scyllo-inositol and m yo-inositol. On oxidation, it yields a new t rik eto-inositol, xylo-4,5, 6-trihydroxycyclohexane-1 ,2,3-tri one (II).U nd er acidic cond iti ons, catalytic acetylation of 1 gives two pen taacetates, t he infrared sp ectra of whi ch arc simil a r but n ot id ent ical. One of t hese acetates ex ists in t wo form s, b oth of whi ch , on deacetylation, yield th e pa ren t ac id 1. Th e product form ed by deacetylation of th e othe r pentaacetate has not bee n identifi ed. Benzoylation of I gives a crystallin e p en taben zoate.Unde r basic condition s, acetylation of I proceed s with simultaneous a rom atization, r esultin g in the formation of pentaacetoxybenzene, from whi ch pentah ydrox ybenzene is obtained b y h ydrolys is.xylo-4,5, 6-Trih yd roxycyclohexane-1 ,2,3-trion e (II) gives a crystalline bis(phenylhydrazon e). B y acetylation under basic condi t ion s, it y ields hexaacetoxy ben ze ne.M echanisms are presented for t he a romatization of keto-inositols by en oli zation a nd beta elimin ation-reactions, a nd ce rtain observations reported in t he li teratme a re rationali zed. Infrared and ult raviolet a bso rp t ion spectra a re reported for t he n ew compou nd .

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Ueber Hexaoxybenzolderivate und ihre Beziehungen zur Krokonsäure und Rhodizonsäure

Cited by 32 publications

References 2 publications

Three Queries about the HOMA Index

Three Queries about the HOMA Index

The Fermentation of Inositol by Propionibacterium Pentosaceum

Cyclic polyhydroxy ketones. II. xylo-trihydroxycyclohexenediolic acid and keto-inositols

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