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Alkylation of 7 - methoxy - 8 - methyl - 1 - tetralone (9) with α-bromopropionic acid provided a stereoisomeric mixture of the keto-acid (10). The isomers (10a and 10b) on sodium borohydride reductions afforded respectively the title compounds (12 and 13). Similar reduction of a stereoisomeric mixture of 17, on the other hand, produced two cis-lactones (19 and 20), the hydroxy-acid (30) and the trans-lactone (22). Sodium borohydride reduction of the simple keto-acid (18) furnished initially the cis-lactone (21) and a mixture of hydroxy-acids (31). This hydroxy-acid on lactonisation gave a separable mixture of 21 and 24. The steric effect of the peri-Me group on the stereochemical outcome of sodium borohydride reduction of the keto-acid (10) has been clearly demonstrated. It has also been pointed out that the difference in the NMR signals for C—6 benzylic protons of the C—11 epimeric cis-lactones, reported here and in the literature, may serve as a diagnostic tool for elucidating the stereochemistry of the C—11 Me groups of these lactones.

Summary Reduction of indanone (I), tetralone (II) and benzosuberone (III) was studied by d. c. and pulse polarography, cyclic voltammetry and controlled potential electrolysis with a dropping mercury electrode in aqueous solutions containing 2% ethanol at various pH values. In acidic media the protonated form, at higher pH values the free carbonyl form is reduced. The reduction of the unprotonated form is accompanied by protonation of the radical anion formed. The behavior of all three ketones I–III in this pH region is similar and differs only in the half-wave potential values and the rates of protonation of the radical anion. The reduction of the protonated form is affected both by differences in potentials of the ketones I–III and by differences in the rates of protonation, but most significantly by the half-wave potential of the radical formed in the first electron uptake. For indanone (I) this reduction is so positive that only one two-electron step is observed. For benzosuberone (III) the half-wave potential of this reduction is sufficiently more negative than the first electron uptake and two one-electron separated waves result. For tetralone (II) the reduction of the radical occurs at so negative a potential that it is overlapped by the hydrogen evolution current. Only one one-electron wave is thus observed. The effect of ring size on potentials and protonation reactions is discussed from the point of view of ring strain, adsorbability and radical stability.

The out-of-plane CH deformation vibrations of the aromatic ring of the tetralin series normally appear in almost the same frequency region as in the corresponding benzene series, and their frequencies are regularly shifted by the type of substituents attached to the aromatic ring with a few exceptions. All compounds which have an isolated CH group in the aromatic ring exhibit fairly strong absorption bands around the 800 cm−1 region, which may be associated with the aromatic ring. Carbonyl and hydroxyl groups in the peri-position of tetralone are strongly chelated, showing frequency shifts in their stretching vibrations.

The proton NMR spectra of a series of 2-benzal-, 2-benzyl-, and 2-benzyl-2-bromo-indanones and a series of substituted 4,4-dimethyltetralones have been determined. The cis and trans isomers of 2-benzalindanones are easily identified through analysis of their PMR spectra. Peculiarities in the complex spectra of 2-benzyl and 2-benzyl-2-bromoindanones and tetralones are partially accounted for on the basis of conformational preference about the carbon-carbon bond attaching the 2-benzyl moiety to the 2-position of the indanone and tetralone rings. An internal complexation between the benzyl phenyl and the carbonyl group may be involved in some of these structures. The 4,4-dimethyltetralones exhibited two methyl resonances as a result of substitution in the 2-position and the stereo-structures are discussed in terms of conformational analysis.

Enamine Ia , derived from 6-methoxy-1-tetralone and morpholine, reacts with carbenes 1 2a and 2b to give (1:1) adducts 3a , and a mixture of 3b and 3c , respectively. The pyrrolidine enamine 1b , on the other hand, reacts with carbene 2b , to give, beside the (1:1) adduct 3e , benzylidene-derivative 4b . Reaction of enamine 1b with carbene 2a does not yield a 1:1 adduct; instead, two products were isolated which have been identified as 4a and 5 . Both morpholine and pyrrolidine enamines 1ab , react with carbene 2c to give one and the same product 6. Possible mechanisms for the formation of the reaction products are discussed.

The radiolysis of benzene, toluene, cumene, tetralin and indan was investigated in the presence of NO under the influence of 60Co-γ-rays and 2-MeV electrons, respectively. As main products of the benzene-NO system were found: biphenyl (GA = 0·08), nitrobenzene (GA = 0·024), nitrogen (GA = 2·1), hydrogen (GA = 0·02), apart from small amounts of phenylcyclohexadiene, p-terphenyl, phenol, nitrosobenzene and nitrogen containing polymers. The toluene-NO system yielded: benzyl nitrate (GA = 0·28), bibenzyl (GA = 0·07), benzaldehyde (GA = 0·22) and as byproducts: dimethylbiphenyl, benzylmethylcyclohexadiene, benzyl alcohol, benzoic acid and nitrogen containing polymers (G = 1·1). By irradiating the cumene-NO system were formed: α-nitrocumene, cumylnitrate, acetophenone and polymers. In the mixture obtained from the tetralin-NO system the following could be identified: nitrotetralin, nitrate ester of tetralol, and tetralone, whereas 3-nitroindene was isolated from the mixture of products of the indan-NO system.

The intramolecular cyclization of 50/50 styrene-acrylic acid (or derivatives) copolymers has been investigated; the purpose of this work was the synthesis of a high molecular weight poly-2,4-methylenetetralone. The cyclization of styrene-(meth)acroyl chloride copolymers in the presence of aluminum chloride gives under rather mild experimental conditions high yields of tetralone units, together with some tricyclic units of the hexahydrophenalenedione type. This cyclization reaction was, however, always concomitant with a strong degradation of the polymeric chains: it results from the formation of a carbonium ion on the main chain through a secondary decarbonylation reaction, as shown by chemical determination. The cyclodehydration of a styrene(meth)acrylic acid copolymer was carried out with good yields in an acetylating mixture, in the presence of various catalysts such as zinc chloride, polyphosphoric acid, or phosphorus oxychloride. The cyclization to tetralone units is concomitant with the formation of anhydride groups, and in the case of acrylic acid, of enol-ester groups: the alkaline hydrolysis of the products yields terpolymers of styrene, acrylic acid, and methylenetetralone. Moreover, using polyphosphoric acid or phosphorus oxychloride, the intrinsic viscosity of the cyclized copolymers remains important, even at rather high degree of conversion. The cyclization of styrene-methyl(meth) acrylate copolymers in heterogeneous medium, in polyphosphoric acid, was also carried out; the degradation process is very small. The methacrylic ester copolymers undergo, however, an important gelification, while the acrylic copolymers yield, besides the usual tetralone units, some tetracyclic units of the tetrahydro-3,4-benzophenanthrene type.

Ten kinds of hydroxytetralone oximes have been synthesized and their reactions with metallic ions have been investigated. It was found that the tetralone oxime having a hydroxyl group at the 8-position reacted with Cu2+, Ni2+, and Co2+, etc., forming insoluble, colored precipitates; but those containing no hydroxyl group at the 8-position or those having inactivated 8-methoxy or 8-acetoxy groups did not form the precipitate. The precipitate was found to be an intramolecular complex salt of the metal and the oxime by analysis of the compound and from the solubility of the precipitate in chloroform. 8-Hydroxy-5-methoxytetralone oxime had an especially sensitive reaction with metallic ions, and this could be utilized as a spot test reagent. Also, the chloroform solution of the complex salt of this oxime with Cu2+ and Ni2+ gave light yellow and light green colorations withmaximum absorption at 378 mμ and 395 mμ, respectively. The light absorbancy and the ion concentration were linearly related, and this relationship could be utilized in colorimetric determin ations of Cu2+. and Ni2+. The complex salt of Co2+ had an orange color and showed maximum absor ption at 372.5 mμ; but it changed gradually to dark brown, and the absorption finally became obscure.

Three naphthoquinones, isodiospyrin (I), bisisodiospyrin (II), and 7-methyljuglone (IV), a new tetralone derivative named shinanolone (III) and four triterpenes, taraxerol, lupeol, betulin, and betulinic acid, were isolated from the roots of Diospyros japonica. The structure of shinanolone was elucidated to be 4, 8-dihydroxy-6-methyl-1-tetralone and the application of the dibenzoate chirality rule was attempted for the compound.

[1-13C]Naphthalin wurde uber [1-13C]-4-Phenyl-buttersaure (aus 1-Brom-3-phenyl-propan und [13C] Kohlendioxid), [1-13C]Tetralon und [1-13C]Tetralin synthetisiert. 1H-HMR-und 13C-NMR-Spektren sowie das ESR-Spektrum des Radikalanions werden diskutiert. Mit Hilfe der genannten drei magnetischen Resonanzmethoden wurde gezeigt, das eine durch Aluminiumchlorid katalysierte Automerisation des Naphthalins unter den in der Literatur angegebenen10,12 Bedingungen nicht erfolgt. [1-13C]Naphthalene: Synthesis, n.m.r. Spectra, e.s.r. Spectrum of the Radical Anion and the Automerization Problem1 [1-13C]Naphthalene was prepared via [1-13C]-4-phenylbutanoic acid (from 1-bromo-3-phenylpropane and [13C]carbon dioxide), [1-13C]tetralone and [1-13C]tetraline. 1H n. m. r. and 13C n. m. r. spectra are discussed as well as the e. s. r. spectrum of the [1-13C]naphthalene radical anion. By these magnetic resonance measurements it is shown that an automerization of naphthalene catalyzed by aluminium chloride does not occur under the conditions mentioned in literature10,12.

Tetrahydrooxocrinine methine (XLIII) has been synthesized by a sequence of reactions including ring enlargement of a tetralone (XXXVI) to a seven-membered nitrogenous ring compound (XXXVIII) by the use of Schmidt reaction.

The investigation of α - and β -aminoketones derived from thiophene isosteres of 1-indanone and 1-tetralone is described. Preliminary pharmacological data are provided.

Die Bestrahlung der Mannichbasen I bis VI fuhrt hauptsachlich zu β-Iminoketonen. Daneben werden Benzo-dihydroindole und Indeno-pyrrole gebildet. VI erleidet auserdem eine Norrish-II-Spaltung. Photoreaction of Tetralone- and Indanone-Mannich Bases Irradiation of Mannich Bases I to VI leads mainly to β-iminoketones. Besides benzo-dihydroindoles and indeno-pyrroles are obtained and VI suffers a fragmentation in a kind of Norrishtype II-process.

The course of the oxidation of some cyclic ketones (including tetralone and cyclohexanone) by FeCl3 is elucidated. Mechanisms of hydrolysis of 2-chlorocyclohexanone and 2,2-di-chlorocyclohexanone under acidic conditions are also discussed.

Analysis of the products formed during oxidation of tetralin in acetic acid has clarified the course of the reaction. The primarily formed hydroperoxide decomposes to an equimolar mixture of α-tetralol and α-tetralone. α-Tetralol is further oxidized (to α-tetralone) at a higher rate than the rate of tetralin oxidation. Thus, it is found that the ketone to alcohol product ratio increases with increasing degree of conversion. This ratio, however, is essentially independent of the concentration, composition or even physical state of the catalyst. α-Tetralol is also oxidized at the 4-position, and the previously undescribed 1,4-disubstituted naphthalene derivatives, 1,2,3,4-tetrahydro-1,4-dihydroxynaphthalene and 1,2,3,4-tetrahydro-1-keto-4-hydroxynaphthalene, have been isolated and identified. The products, α-naphthol and dihydronaphthoquinone, which were also isolated, explain the autoinhibition observed at high conversion. The ketone to alcohol product ratio obtained on decomposition of the hydroperoxide in the absence of air was also shown to depend on the degree of conversion. α-Tetralone is the main product formed at temperatures exceeding 100°. Separate oxidation studies of α-tetralol and α-tetralone support the above conclusions on the course of tetralin oxidation.

Electron paramagnetic resonance measurements of the lowest n-π * triplet states of 1-indanone and α-tetralone incorporated substitutionally in a single host of durene have been performed using optical detection at 2.0°K with 35 GHz microwaves.

A formal total synthesis of the hasubanonine alkaloid cepharamine (3b) from 7,8-dimethoxy-2- tetralone has been accomplished. A key intermediate in the synthesis was 3-methyl-1.2.4.5-tetrahydrobenz[e]indole 4a which was prepared by a one step ring expansion reaction of cyclopropyl ketone 8b effected by methylamine. The annelation of 4a with methyl vinyl ketone yielded aminoketone 5a which possesses the tetracyclic skeleton characteristic of the hasubanonine alkaloid group. The oxidation of 5a to 5e. which was reported to have been converted to cepharamine, completed the formal total synthesis of that alkaloid. The foregoing transformations and others related to than have also been carried out in the analogous desmethoxy series of compounds beginning with β-tetralone, 8d.

An analysis of both the aromatic and aliphatic portions of the 1H NMR spectrum of α-tetralone has been carried out. Two deuterated derivatives, 2,2-dideuterio- and 4,4-dideuterio-α-tetralone, were prepared to facilitate unambiguous assignment of chemical shifts for the aliphatic protons. The conformation of the 6-membered alicyclic ring of the molecule is defined by the coupling constants among the aliphatic protons. Benzylic coupling was the only detectable long range interaction between the aliphatic and aromatic protons of the molecule. The magnitude and sign of these coupling constants agree with previous calculations of Wasylishen and Schaefer.

A benzyne type reaction of 1-bromo-3,4-dimethoxybenzene (V) with 3,4-dihydro-6,7-methylenedioxy-I(2H)naphthalenone (VI) gave the tetralone derivative VII, which was converted into the amine IX via the oxime VIII. A Mannich reaction of IX afforded the benzo[c]phen-anthridine II which was then transformed into oxynitidine (I) and nitidine (IV).

The tetralone 2a has been obtained in 45% overall conversion from the dione 3 by the sequence 3 → 4a → 4b → 5b → 5a → 2a.

A biomimetic synthesis of the tetralone scytalone from methyl curvulinate is described; some bio-synthetic implications such as aromatic dehydroxylation are discussed.

A convenient route to chrysene derivatives has been developed on the basis of cationoid reaction between aromatic substances and \(\gamma\)\(\delta\)-unsaturated ketones, and the synthesis of 2-methyl- and 2:5-dime­thylchrysene by this route is described.

A biomimetic synthesis of the tetralone scytalone from methyl curvulinate is described; some bio-synthetic implications such as aromatic dehydroxylation are discussed.

Aus den l-Tetralonoximen (I) erhalt man beim Erhitzen mit Essigsaureanhydrid und wasserfreier Phosphorsaure die Amide (II), aus dem Tetrahydrophenanthrenketonoxim (III) entsteht analog das Amid (IV).

The title compound has been prepared from 4-hydroxy-3,5-dimethoxybenzaldehyde by a Stobbe tetralone carboxylic acid synthesis.

Although deoxyanisoin underwent fission on attempted reaction with sodium or lithium acetylide in liquid ammonia, it condensed normally with 1-hexyne and propyne via the Grignard reagent, the intermediate aoetylenic carbinols dehydrating on distillation. The reaction of acetylenedimagnesium bromide and deoxyanisoin at room temperature afforded the stable 1,2-di-(p-methoxyphenyl)but-3-yn-2-ol, whereas the same reagents under more vigorous conditions resulted in cyclization to 2-methoxy-6-p-methoxyphenylnaphthalene, synthesized from anisil or deoxyanisoin by a Reformatsky reaction via the tetralone.

The axial preference in dihydronaphthalene (III) and in a tetralone (VI) has been established by n.m.r. spectroscopy; the conformational equilibrium in the ketone was detected by c.d. measurements.

Attempts have been made to effect fragmentation reactions with bromo- tetralone systems related to 6α-bromo-13-hydroxytotara-8,11,13-trien-7- one (VII), a compound which affords a secoditerpenoid (IX) when treated with DMSO-NaHCO3. On treatment with sulphuric acid in acetone, the mono- epoxide derivative (XXVIII) of the methyl ether of the secoditerpenoid undergoes a novel aromatization to a naphthalenic aldehyde (XXXI) by successive transannular cyclization and fragmentation reactions. ��� A 7β-hydroxy configuration has been confirmed for the major product from reduction of 13-acetoxytotara-8,11,13-trien-7-one (VIII) with lithium aluminium hydride. 13-Methoxytotara-8,11,13-triene (II) has been deisopropylated and then subjected to Birch reduction in an attempt to effect a high yield conversion into (+)-podocarp-8(14)-en- 13-one (XXXVII), a potentially useful intermediate for synthesis.