bluuebunny/crossref_metadata_2025_split huggingface dataset:
Rearrangements in polyhedric foam
Authors: Schwarz H. W. 
Published: September 2010

AbstractThe process of rearrangement of lamellae in polyhedric foam is described, and rules for the course of these rearrangements are given.It is shown that in polyhedric foam the lamellae and Plateau borders should be curved in general to fulfil the requirements that the angles between the lamellae are 120° and those between the Plateau borders 109°28′.
Untersuchungen über N‐Oxyde des 2‐Dimethylaminopyridins II
Authors: Wieczorek J. S. , PłLażek E. 
Published: September 2010

AbstractBei der Nitrierung des N2‐Oxydes des Dimethylaminopyridins (II) entsteht das 2‐Dimethylamino‐5‐nitropyridin; die gleiche Verbindung wurde bei Nitrosierungsversuchen erhalten. Durch eine weitere Oxydation des N1‐Oxydes (I) des 2‐Dimethylaminopyridins wurde das N1,N2‐Dioxyd erhalten (III). Es wurde gefunden das sich das N2‐Oxyd des Dimethylpyridins und das N‐Oxyd des Dimethylanilins, nicht aber das N1‐Oxyd des 2‐Dimethylaminopyridins in einfacher Weise mit CS2 desoxydieren lassen. Aus dem N1,N2‐Dioxyd des 2‐Dimethylaminopyridins entsteht mit CS2 das N1‐Oxyd. Bei der Nitrierung des N1,N2‐Dioxydes entsteht das N1‐Oxyd des 2‐Dimethylamino‐5‐nitropyridins.
Electronic spectra of nuclear methyl‐substituted 1,1‐diphenylethylenes
Authors: Korver O. , Veenland J. U. , de Boer Th. J. 
Published: September 2010

AbstractThe electronic spectra of nuclear methyl‐substituted 1,1‐diphenylethylenes in ethanol, cyclohexane and in 98% sulfuric acid are discussed.
Chemistry of acetylenic ethers: 78 Isomerization of some conjugated enyne compounds
Authors: van Boom J. H. , Montijn P. P. , Berg M. H. , Brandsma L. , Arens J. F. 
Published: September 2010

AbstractEnyne‐hydrocarbons, ‐alcohols and ‐ethers with the systemcan be converted into the isomers with a terminal acetylenic group, by treating them with an excess of potassium amide in liquid ammonia and hydrolysing the reaction mixture thus formed. In most cases yields are excellent.Enyne thioethers RCC‐CHCH‐SC2H5(R  alkyl) undergo an elimination of ethanethiol under these conditions. Hydrolysis affords the 1,3‐diynes RCC‐CCH in very good yields.
The constitution of the Grignard Reagent: Part V. On the possibility of an equilibrium between ethylmagnesium bromide and diethylmagnesium
Authors: Blomberg C. , Vreugdenhil A. D. , van Zanten B. , Vink P. 
Published: September 2010

AbstractThe possibility of the existence of an equilibrium in diethyl ether between ethylmagnesium bromide ‐ prepared from 14C‐labelled ethyl bromide and magnesium ‐ and diethylmagnesium was investigated. The result was inconclusive because complete exchange of ethyl groups was found which might be attributed either to the existence of an equilibrium or to a transmetallation reaction.
Phosphonate analogs of cephalin
Authors: Rosenthal Arthur F. , Pousada Manuel 
Published: September 2010

AbstractTwo ester‐phosphonate analogs of cephalin of the typemagnified image
have been synthesized in the L‐dipalmitoyl (R  C15H31) and DL‐distearoyl (R  C17H35) forms. 2‐Phthalimidoethylphosphonic acid was prepared by hydrogen bromide cleavage of its crude diethyl ester. Reaction of D‐αβ‐dipalmitin or DL‐αβ‐distearin with 2‐phthalimidoethylphosphonyl dichloride gave, after hydrazinolysis and purification of the product on a silicic acid column, the corresponding phosphono‐cephalins (I).A diether‐phosphonate analog of cephalin,magnified imagewas prepared in high yield by condensation ofmagnified imagewith 2‐hydroxyethylphthalimide and trichloroacetonitrile, followed by hydrazinolysis of the phthalyl diether phosphonocephalin.
Investigations on sterols XXIV: Synthesis of some 6‐dehydro‐8α, 10α‐steroid hormone analogues and conversion of 8β, 10α‐ into 8α, 10α‐steroids
Authors: van Moorselaar R. , Halkes S. J. , Havinga E. 
Published: September 2010

AbstractThe synthesis of some 6‐dehydro‐8α,10α‐steroids from 10α‐ergosterol (pyrocalciferol) is described. 17β‐Hydroxy‐8α,10α‐androsta‐4,6‐dien‐3‐one (XI) has also been prepared from 17β‐hydroxy‐10α‐androst‐4‐en‐3‐one 17‐acetate (XIV).
Investigations on sterols XXVIII: Synthesis of 6‐methyl‐9β,10α‐steroids; conformation of ring B in 4‐en‐3‐one derivatives
Authors: van Kamp H. , Halkes S. J. 
Published: September 2010

AbstractThe synthesis is described of 6‐methyl‐9β,10α‐4‐en‐3‐ones, which were dehydrogenated to some of their 1‐dehydro, 6‐dehydro and 1,6‐bisdehydro derivatives. N.M.R. spectra reveal that ring B in 6α‐methyl‐9β,10α‐4‐en‐3‐ones has a boat conformation. The factors forcing ring B into a boat form are discussed. A summary of endocrinological data is given.
The copper‐catalysed oxidation of unsaturated carbonyl compounds: II. Base‐catalysed isomerization of isomesityl oxide and Δ5‐cholestenone
Authors: Volger H. C. , Brackman W. 
Published: September 2010

AbstractThe mechanism of the base‐catalysed isomerization of the βγ‐unsaturated ketones isomesityl oxide and Δ5‐cholestenone to their αβ‐unsaturated isomers was studied. The results are interpreted on the basis of a reaction scheme in which a dienolate anion, formed by deprotonation of the starting material, is an intermediate. The factors determining the rate of deprotonation of unsaturated ketones are discussed.Methoxide ions were found to deprotonate both ketones studied, whereas triethylamine, which deprotonates isomesityl oxide directly, was found to react with Δ5‐cholestenone only via the intermediate formation of methoxide ions from the solvent methanol.
Gas hydrates of nitrogen and oxygen. II
Authors: van Cleeff A. , Diepen G. A. M. 
Published: September 2010

Abstractp‐t relations of different three phase equilibria in the systems nitrogen‐water and oxygen‐water are given from ‐6 to 18° for pressures up to 1000 atm. From the data, the heats of formation of nitrogen‐ and oxygen‐hydrate and the composition of these hydrates were calculated.
Syntheses of amino and bromo derivatives of 4‐methyl‐, 4‐t‐butyl‐ and 4‐phenyl‐pyrimidine
Authors: van der Plas H. C. 
Published: September 2010

AbstractA description is given of syntheses of 5‐amino, 6‐amino and 5‐bromo derivatives of 4‐methyl‐, 4‐t‐butyl‐ and 4‐phenyl‐pyrimidine, using 6‐hydroxy‐4‐methyl‐, 4‐t‐butyl‐6‐hydroxy‐ and 6‐hydroxy‐4‐phenyl‐pyrimidine as starting substances.
Mesures de pH dans des Mélanges Eau‐éthanol
Authors: Gelsema W. J. , de Ligny C. L. , Visserman Melle G. F. 
Published: September 2010

AbstractSuivant la méthode du National Bureau of Standards à Washington les valeurs pHs* ont été déterminées d'un tampon oxalique et d'un tampon succinique dans l'eau et quelques mélanges eau‐éthanol ainsi que celles d'un tampon salicylique et d'un tampon diéthylbarbiturique dans l'éthanol absolu. Par des mesures de f.é.m. de cellules à jonction saline il est possible de montrer que les potentiels de diffusion entre ces solutions‐tampons standard et une solution aqueuse saturée de chlorure de potassium dépendent uniquement de la teneur en éthanol du solvant et non pas de la nature du tampon, ce qui a permis la détermination des valeurs pHs* du tampon diéthylbarbiturique dans l'eau et quelques mélanges eau‐éthanol.Utilisant les solutions‐tampons standard, les constantes de dissociation de plusieurs acides des types HA et BH+ont été mesurées dans l'eau et quelques mélanges eau‐éthanol. Il s'ensuit des résultats que les fonctions d'acidité H−et H0ne sont pas des mesures sans équivoque de l'acidité dans ces milieux. La faible basicité de la propylamine et de la butylamine par rapport aux autres amines primaires aliphatiques est expliquée par l'existence d'une liaison hydrogène intramoléculaire du type C‐H …. N. De même, une liaison hydrogène intramoléculaire du type C‐H …. O est responsable de la faible acidité de l'acide propionique par rapport aux autres acides carboxyliques. L'influence de substituants sur les valeurs pK*‐pK est attribuée principalement à un empêchement à la solvatation des ions organiques, croissant avec le nombre de molécules d'éthanol solvatées. Dans les cas de l'ammoniac et de l'aniline on peut démontrer que même le substituant méthyle exerce un tel effet stérique.
Hammett and Taft‐Ingold relations in heterocyclic compounds
Authors: ten Thije P. A. , Janssen M. J. 
Published: September 2010

AbstractAcid and base catalysed hydrolysis rates were determined for the ethyl esters of 2‐ and 3‐furoic acids and 2‐ and 3‐thiophenecarboxylic acids. From the data, σ* values were derived for the 2‐ and 3‐furyl‐ and ‐thienyl grpups. The dissociation constants (pKa) of the acids are proportional to the σ* values of the appropriate groups and it appeared that benzoic acid fits the same relation.From a study of the hydrolysis of 5‐substituted 2‐thiophenecarboxylic esters (methyl, chloro, bromo and nitro substituents were covered) it was found, that the alkaline hydrolysis rates could adequately be related by a set of substituent constants σth, which are rather similar to σm in the benzene series. However, both the acidic hydrolysis rates of the same esters, and the chemical shifts of the methyl protons of 5‐substituted 2‐methylthiophenes show large deviations from this relation.
Acid anilides: XII. The preparation of 4‐ and 5‐hydroxyalkananilides from γ‐ and δ‐lactones
Authors: de Jonge A. P. , van der Ven B. 
Published: September 2010

AbstractThe preparation of 4‐ and 5‐hydroxyalkananilides from minute amounts of lactones is discussed. In addition, the solubility of two 5‐hydroxyalkananilides in cyclohexane was determined.The rate of hydrolysis of hydroxyalkananilides by hydrochloric acid has been determined spectrophotometrically.
Studies on imidazoles, part I: The action of phosphorus pentachloride on N‐butyl‐N′‐ethyloxamide
Authors: Trout G. E. , Levy P. R. 
Published: September 2010

AbstractTwo isomeric 5‐chloro‐1,2‐dialkylimidazoles, obtained by the action of phosphorus pentachloride on N‐butyl‐N′‐ethyloxamide, have been isolated and their structure determined.
Chemistry of acetylenic ethers 80 1‐acylthio‐1‐alkynes, a new class of compounds
Authors: Wijers H. E. , Montijn P. P. , Brandsma L. , Arens J. F. 
Published: September 2010

Abstract1‐Acylthio‐1‐alkynes magnified image (R and R′ are alkyl) have been prepared in satisfactory yields from ethereal suspensions or solutions of alkynyllithium R′CLi, sulfur powder, and acyl bromides magnified image.Addition of water at 60‐70° to magnified image proceeds smoothly with formation of magnified image. This product is identical with a sample prepared from magnified image.
Kinetic protium‐deuterium isotope effect in an intramolecular 1–5 shift of hydrogen
Authors: Kloosterziel H. , ter Borg A. P. 
Published: September 2010

AbstractThe thermal isomerization of 5,8‐dideuterocycloocta‐1,3,6‐triene to the 1,3,5‐isomer has been studied. From the rate, as compared with that of the unlabelled compound, and from the distribution of the label in the rearranged material, values were obtained for the primary and secondary kinetic isotope effects. The large value of 5.0 at 120° for the former tallies with a nearly symmetrical transition state.
Racemisation during peptide synthesis with 1‐alkynylamines (ynamines)
Authors: van Mourik A. S. , Harryvan E. , Arens J. F. 
Published: September 2010

AbstractThe Anderson‐Young test was applied to peptide syntheses in which 1‐dialkylamino‐1‐alkynes (ynamines) were used as condensing agents. Considerable racemisation was observed.PHT‐L‐phe anhydride could be obtained from PHT‐L‐phe and 1‐diethylamino‐1‐pentyne without racemisation, provided that no excess of reagent was used.
Energy data on the carbon‐carbon bond VII heats of dissociation of some symmetrical tetra‐arylethanes measured by electron spin resonance
Authors: Fleurke K. H. , de Jong J. , Nauta W. Th. 
Published: September 2010

AbstractThe heats of dissociation of some ortho alkyl‐substituted tetraphenylethanes which show reversible thermal dissociation in solution at room temperature, were measured by means of ESR. The values found are 22.0, 19.7 and 12.0 kcal/mole for symm.tetra(2,6‐dimethylphenyl)ethane, symm.tetra(2‐tert‐butyl‐phenyl)ethane and symm.tetra(2,6‐diethylphenyl)ethane, respectively.
Internal reactions in the Grignard‐complex containing compounds with alkoxy‐groups part III: Allyl phenyl ether
Authors: Blomberg C. , Vreugdenhil A. D. , Vink P. 
Published: September 2010

AbstractThe reaction of methylmagnesium iodide with allyl phenyl ether was investigated. Contrary to expectation2 1‐butene, the product of the ether cleavage reaction, was formed only to a small extent, the main gaseous product being methane. The mechanism proposed for the formation of this product is: Claisen rearrangement of allyl phenyl ether under the influence of magnesium iodide and reaction of methylmagnesium iodide with the rearrangement product, o‐allylphenol with formation of methane. The formation of methane as well as of 1‐butene indicates that two competitive reactions (rearrangement and ether cleavage reaction) take place.
Derivatives of benzo‐ and indolo‐quinolizines II. Synthesis of 2‐substituted hexahydro‐2h‐benzo[a]quinolizines and octahydroindolo[2,3‐a]quinolizines from substituted valerolactones
Authors: Gootjes J. , Nauta W. Th. 
Published: September 2010

AbstractThe preparation of a number of 2‐substituted 1,3,4,6,7,11b‐hexahydro‐9,10‐dimethoxy‐2H‐benzo[a]quinolizines and 1,2,3,4,6,7,12,12b‐octahydroindolo[2,3‐a]quinolizines is described. Starting from 3‐substituted valerolactones, the preparation required five stages (see Reaction Scheme I). A number of the 3‐substituted valerolactones used were conveniently prepared by reduction of the corresponding glutaric acid derivatives, e.g. the anhydrides, with sodium borohydride. The final stage is a stereoselective reduction, leading to cis or trans isomers. The synthesis and data of one of the end‐products, 1,3,4,6,7,11b‐hexahydro ‐9,10‐dimethoxy‐2‐phenyl‐2H‐benzo[a]quinolizine, are compared with those reported for this compound by Tomimatsu.
Experiments in the 5H‐dibenzo[a,d]cycloheptene series II. Synthesis of some esters and piperazine derivatives of 5H‐dibenzo[a,d]cycloheptene
Authors: van der Stelt C. , Haasjes A. , Tersteege H. M. , Nauta W. Th. 
Published: September 2010

AbstractThe synthesis of a number of acids in the 5H‐dibenzo[a,d]cycloheptene series is described including the 5‐carboxylic acid and its 10,11‐dihydro analogue, 5H‐dibenzo[a,d]cycloheptene‐5‐acetic acid and its 10,11‐dihydro derivative. The latter acid was prepared by several routes. Treatment of its acid chloride with stannic chloride yielded 2,6,7,1 1b‐tetrahydro‐1H‐dibenzo[c,d,h]azulen‐2‐one, which by reductive amination with methylamine, dimethylamine and 1‐methyl‐phenethylamine was converted into the corresponding amines. Several esters with aliphatic and heterocyclic amino alcohols were prepared from the carboxylic acids mentioned. The acids were likewise converted into 1‐substituted 4‐piperazides which were reduced to the corresponding piperazine derivatives. The acid derivatives were screened for biological activity.
The crystal structure of 6,6‐dibromo‐2,3:4,5‐dimethano‐2,4‐dinitrocyclohexanone
Authors: Stam C. H. , Evers H. 
Published: September 2010

AbstractThe crystal structure of 6,6‐dibromo‐2,3:4,5‐dimethano‐2,4‐dinitrocyclohexanone has been determined in order to find the positions of the two cyclopropyl rings relative to the carbonyl group.
The NMR spectrum of the cyclic trimer of glycidaldehyde
Authors: Jungnickel J. L. , Reilly C. A. 
Published: September 2010

AbstractA sample of glycidaldehyde cyclic trimer, 2,4,6‐tris(epoxyethyl)‐1,3,5‐trioxane, yielded an NMR spectrum more complex than expected. From its method of preparation, it must be a cis‐cis isomer of the chair form, with all three epoxyethyl groups equatorial. The complexity of the spectrum has been explained in terms of asymmetric carbon atoms, the sample being a racemic mixture of ddl and lld forms. A second form, with a simpler spectrum, has been identified with the ddd + lll racemate. This interpretation is believed to explain also a complex spectrum of parabutylchloral obtained by Barón and Hollis.
The formylation of ketones
Authors: van der Zeeuw A. J. , Gersmann H. R. 
Published: September 2010

AbstractFormylation of ketones with carbon monoxide to give α‐formyl ketones under the influence of alkali metal alkoxides in dimethoxyethane (DME) can occur in two ways. With primary alkoxides as bases, formylation takes place via alkyl formates. Addition of the corresponding alcohol favors the reaction. When potassium tert‐butoxide is used, besides this indirect reaction, a direct reaction of the ketone anion with CO occurs. In the absence of alcohols e.g. when the ketone is ionized by potassium naphthalene only the direct reaction occurs; its mechanism has been studied in more detail.
Changes in ultraviolet absorption of aldoses during thermal decomposition in dilute aqueous solution
Authors: Berrens L. 
Published: September 2010

AbstractHeating of dilute aqueous solutions of simple aldoses at 50° induces marked alteration in the electronic absorption spectra of the sugars. Maxima at 230 mμ and 275 mμ, and low‐intensity peaks at 325 mμ and 350 mμ, appear as a function of the time of heating and of pH. These maxima are attributed to intermediates in the degradation of aldoses; the absorption peaks at 230 and 325 mμ in particular are concluded to represent the K‐ and R‐bands in the spectrum of the enolic forms of 3‐deoxyglycosuloses.
The photocurrent in anthracene crystals under illumination of the negative electrode
Authors: Mulder B. J. , de Jonge J. , Vermeulen G. 
Published: September 2010

AbstractPhotocurrents in anthracene crystals (with electrolytic electrodes) generated by strongly absorbed light (25000‐30000 cm−1) have their origin exclusively at the surface of the crystal in contact with the positive electrode. Photocurrents observed under illumination of the negative electrode arc the result of reabsorption of fluorescent light.
A new γ‐lactone found in butter
Authors: Lardelli G. , Dijkstra G. , Harkes P. D. , Bolding J. 
Published: September 2010

AbstractA characteristic component of butter flavour is 2,3‐dimethyl‐2,4‐nonadien‐4‐olide, the enol lactone of 2,3‐dimethyl‐4‐oxo‐2‐nonenoic acid. Homologues have not been found. The substance which has a strong odour reminiscent of celery and occurs in an amount of about 0.5 mg/kg butter, was called “bovolide”.The elucidation of its structure and its synthesis are described. Also several related compounds have been synthesized.
Energy data on the carbon‐carbon bond VIII activation energies of the dissociation of some symmetrical tetra‐arylethanes
Authors: Fleurke K. H. , Nauta W. Th. 
Published: September 2010

AbstractThe activation energies of the dissociation of some ortho‐alkyl‐substituted symmetrical tetraphenylethanes were determined by measuring the reaction rates of these compounds with oxygen in m‐xylene solutions. The values found are 25.3, 22.9 and 19.6 kcal/mole for symm.tetra(2‐tert‐butylphenyl)ethane, symm.‐tetra(2,6‐dimethylphenyl)ethane and symm.tetra(2,6‐diethylphenyl)ethane, respectively. The frequency factors and activation entropies of the dissociation reaction were obtained from the same measurements. Using the known data on the dissociation equilibria, we also calculated the relevant kinetic values for the recombination reactions.
On the structure of α‐UO3
Authors: Loopstra B. O. , Cordfunke E. H. P. 
Published: September 2010

AbstractFrom the neutron diffraction pattern of a‐UO3 it was found that the generally accepted hexagonal structure is incorrect. Both chemical and structural arguments have led us to regard a‐UO3 as an imperfectly crystalline form of the orthorhombic modification generally called UO2.9. This substance has an unknown structure which is shown to be disordered.
Synthesis and physiological properties of some heterocyclic‐aromatic sulfides and sulfones. V: Synthesis of some ring‐substituted aromatic ethene thioethers and their corresponding sulfones
Authors: Trompen W. P. , Huisman H. O. 
Published: September 2010

AbstractThe synthesis of some ring‐substituted aromatic ethene thioethers and their corresponding sulfones is described. The acaricidal activity and ovicidal action on eggs of Tetranychus urticae, Koch are reported.
Studies in homogeneous catalysis: Copper‐phenanthroline complexes as catalysts for the oxidation of methanol
Authors: Brackman W. , Gaasbeek C. J. 
Published: September 2010

AbstractCopper phenanthroline complexes are catalysts for the oxidation of methanol by oxygen at 30‐45 °.A feature of the reaction is that it shows an induction period unless started with small amounts of H2O2 or cuprous ion. During the reaction the system contains a considerable amount of cuprous complex, the presence of which appears to be an essential condition for the continuation of the oxidation.Hydrogen peroxide, in contrast to other hydroperoxides, rapidly forms cuprous complex when added to a cupric‐phenanthroline system. This reaction probably proceeds via formation of O2−. from HO2− ion and cupric complex. The radical ion \documentclass{article}\pagestyle{empty}\begin{document}\[{\rm O}_{\rm 2}^{-\bullet}\]\end{document} would then abstract a hydrogen atom from methanol (or methoxide) coordinated to cupric‐phenanthroline complex, while simultaneously the cupric ion would abstract an electron from the methanol ligand, thus giving rise to formaldehyde and a proton without the intervention of free methanol radicals. The HO2− ion formed in this reaction would either be reoxidized by cupric complex (chain propagation) or reductively split by a cuprous‐phenanthroline complex (termination).The reactions leading to the hydrogen peroxide‐induced formation of cuprous complex probably constitute an essential part of the mechanism of the copper‐phenanthroline‐catalysed oxidation of methanol by oxygen. In this latter reaction \documentclass{article}\pagestyle{empty}\begin{document}\[{\rm O}_{\rm 2}^{-\bullet}\]\end{document} is supplied by the reaction of cuprous complex with oxygen.
ESR spectra of some diarylmethyl radicals
Authors: de Jong J. , Fleurke K. H. , van Hardeveld R. 
Published: September 2010

AbstractThe ESR spectra of four ortho‐alkyl‐substituted diphenylmethyl radicals have been measured in solutions of m‐xylene. The proton coupling constants were assigned experimentally such that the reconstructions of the spectra agreed with the recorded tracings. The spin densities were calculated assuming proportionality between proton coupling constant and spin density on the adjacent carbon atom. The relation between spin distribution and steric configuration of the radicals is considered on a qualitative basis.
Investigations into the prins reaction with 1‐dodecene
Authors: Heslinga L. , van Gorkom M. 
Published: September 2010

AbstractAddition of protonated formaldehyde to 1‐dodecene in acetic acid solution yields 4‐decyl‐1,3‐dioxane and both cis‐ and trans‐4‐acetoxy‐3‐nonyltetrahydropyran as major products. The configuration of these reaction products was investigated by proton magnetic resonance. Their formation is explained by a recently reported reaction mechanism.
Syntheses of carotenoidal compounds. III: Condensation of polyene‐aldehydes with 1,4‐dicyano‐2‐butene
Authors: Haeck H. H. , Kralt T. 
Published: September 2010

AbstractPreparation, reactions and spectra of condensation products of β15‐, β17‐, β20‐ and β22‐aldehyde with 1,4‐dicyano‐2‐butene are described.
Experiments in the 5H‐dibenzo[a,d]cycloheptene series. III. Synthesis of 10,11‐substituted 5H‐dibenzo[a,d]cycloheptene derivatives
Authors: Corts G. J. B. , Nauta W. Th. 
Published: September 2010

AbstractThe synthesis is described of a number of derivatives of 10,11‐dihydro‐5H‐dibenzo[a,d]cycloheptene, with basic substituents in the ethylene bridge. Moreover, a method is reported for the preparation of amino ethers of 5H‐dibenzo‐[a,d]cyclohepten‐10‐ol.