bluuebunny/crossref_metadata_2025_split huggingface dataset:
Synthese und Chiralität der enantiomeren 6‐Hydroxy‐α‐ionone sowie von cis‐ und trans‐5,6‐Dihydroxy‐5,6‐dihydro‐β‐iononen
Authors: Eschenmoser Walter , Uebelhart Peter , Eugster Conrad Hans 
Published: December 2004

Synthesis and Chirality of the Enantiomeric 6‐Hydroxy‐α‐ionones and of cis‐ and trans‐5,6‐Dihydroxy‐5,6‐dihydro‐β‐iononesWe describe the synthesis of (−)‐(5R,6S)‐5,6‐dihydroxy‐5,6‐dihydro‐β‐ionone (10) and (+)‐(5S,6S)‐5,6‐dihydroxy‐5,6‐dihydro‐β‐ionone (12). The absolute configuration of these compounds has been established by correlation with (R)‐4‐hydroxy‐β‐ionone (1).Therefore, by comparison, the 5,6‐dihydroxy‐5,6‐dihydro‐β‐ionone recently isolated from Rehmannia glutinosa var. purpurea by Endo et al.[4] has the (5R,6R)‐configuration ((−)−12). The same holds for the 5‐β‐D‐glucopyranoside (15) isolated from Aeginetia indica var. gracilis.
Interaction between Exocyclic s‐cis‐Butadiene and Homoconjugated Functions. Preparation and Diels‐Alder Reactivity of Remotely Substituted 2,3‐Dimethylidenebicyclo[2.2.2]octanes
Authors: Avenati Marco , Pilet Olivier , Carrupt Pierre‐Alain , Vogel Pierre 
Published: December 2004

AbstractThe preparations of 5,6‐dimethylidene‐2exo‐bicyclo[2.2.2]octanol (8), its endo isomer 9, 5,6‐dimethylidene‐2‐bicyclo[2.2.2]octanone (10) and 2 exo, 3 exo‐epoxy‐5,6dimethylidenebicyclo[2.2.2]octane (11) are described. The kinetics of their cycloaddition to tetracyanoethylene has been measured in toluene at 25° together with those of 2,3‐dimethylidenebicyclo[2.2.2]octane (7) and 5,6‐dimethylidenebicyclo[2.2.2]oct‐2‐ene (12). The effects of remote substitution on the Diels‐Alder reactivity of 2,3‐dimethyl idenebicyclo[2.2.2]octanes are compared with those observed in the 2,3‐dimethylidenenorbornane series (1–6).
Photochemistry of Aliphatic Imines. The Photochemical Behaviour of Fluorinated N‐Isopropylidenecyclohexylamines
Authors: Margaretha Paul 
Published: December 2004

AbstractThe cyclohexanimines of 1, 3‐difluoro‐2‐propanone and of 1, 1, 1‐trifluoro‐2‐propanone have been synthesized. Their behaviour in acetone‐photosensitized reactions is compared to that of the non‐fluorinated parent compound.
Synthese von [16,16,16,16′,16′,16′‐2H6] Lycopin
Authors: Hofer Arnold , Eugster Conrad Hans 
Published: December 2004

Synthesis of [16,16,16,16′,16′,16′ 2H6]LycopeneLycopene having at both ends the deuteriated methyl groups trans to the chain has been synthesized for further biochemical experiments aimed to elucidate the stereochemistry of the cyclization step.Incidentally a gas‐chromatographic separation of the isotopisomers 1 and 2g has been observed.
The Stereochemical Outcomes – the Isoborneol/Borneol Ratios – in Lithium, Sodium and Potassium/Ammonia Reductions without a Proton Source of the Enantiomers and the Racemate of Camphor Differ Strongly
Authors: Rautenstrauch Valentin 
Published: December 2004

AbstractThe stereochemical outcomes [ratios (1 R, 2 R, 4 R)‐isoborneol/(l R, 2 S, 4 R) isborneol or (1R, 2 S, 4 S)‐isoborneol(l S, 2 R, 4 S)‐borneol and (1 RS, 2 RS, 4 RS)‐isoborneol/(l RS, 2 SR, 4 RS)‐borneol] in lithium, sodium and potassium/ammonia reductions without a proton source of the enantiomeric [(1 R, 4 R) or (1 S, 4 S)] and racemic (1RS, 4RS) forms of camphor under the same conditions differ strongly. This explains contradictory reports in the literature and, in the case of the reductions with potassium in which pinacol coupling does not compete, proves that the reductions involve bimolecular reactions between two ketyls, or between the ketone and the ketyl or the ketone dianion.
Stereochemical Aspects of Acid‐Catalyzed Cyclopropane Ring‐Opening Reactions. A Stereospecific Pathway to Crinosterol and Brassicasterol
Authors: Lang Robert W. , Djerassi Carl 
Published: December 2004

AbstractIt is shown that the acid‐catalyzed ring‐opening of the two diastereoisomeric 23:24‐methylenecholesterols 3 and 5 on treatment with gaseous HCl in acetic acid leads stereospecifically to the naturally occurring crinosterol (4) and brassicasterol (6), respectively (Scheme 1). This isomerization can be viewed as a biomimetic model of an in vivo methylation process of the type already known in plant sterol metabolism (cf. cycloeucalenol → obtusifoliol, 1 → 2). The synthetic application of this method provides a convenient labelling of sterol side chains for tracer experiments. The mechanistic features of the reaction with respect to its particular stereospecificity are discussed.
Macrocyclische Spermidinalkaloide aus Maytenus tnossambicensis (KLOTZSCH) BLAKELOCK 12. Mitteilung über Celastraceen‐Inhaltsstoffe
Authors: Wagner Hildebert , Burghart Joseph 
Published: December 2004

Macrocyclic Spermidine Alkaloids from Maytenus mossambicensis (KLOTZSCH) BLAKELOCKIn addition to celabenzine (1), three new macrocyclic spermidine alkaloids cyclocelabenzine (2), isocyclocelabenzine (3) and hydroxyisocyclocelabenzine (4) have been isolated from Maytenus mossambicensis (klotzsch) blakelock, var. mossambicensis. The three alkaloids show the 13‐membered lactam ring of celabenzine being linked to the benzoyl residue within the spermidine unit. Hydroxyisocyclocelabenzine (4) is the first known spermidine alkaloid with a hydroxy function at the macrocyclus. The structural elucidation was based mainly on spectroscopic methods, specially 1H‐ and 13C‐NMR. spectroscopy.
Herstellung und Eigenschaften einiger hydrocorphinoider Nickel(II)‐Komplexe
Authors: Fässler Alexander , Pfaltz Andreas , Michael Müller Peter , Farooq Saleem , Kratky Christoph , Kräutler Bernhard , Eschenmoser Albert 
Published: December 2004

Preparation and Properties of some Hydrocorphinoid Nickel(II)‐ComplexesCorphin derivatives synthesized earlier in our laboratory have been used for the preparation of tetrahydro‐ and hexahydrocorphinoid nickel(II)‐complexes containing novel chromophore systems. The UV./VIS. and 1H‐ and 13C‐NMR. spectral data of these complexes were relevant to the structure determination of Factor F430 described in the following paper.
Synthese von Glycerylätherphosphatiden 1. Mitteilung Herstellung von 1‐O‐Octadecyl‐2‐O‐acetyl‐sn‐glyceryl‐3‐phosphorylcholin1 (‘Platelet Activating Factor’), des Enantiomeren sowie einiger analoger Verbindungen
Authors: Hirth Georges , Barner Richard 
Published: December 2004

Synthesis of Glyceryletherphosphatides, 1st Communication, Preparation of 1‐O‐Octadecyl‐2‐O‐acetyl‐sn‐glyceryl‐3‐phosphorylcholine (‘Platelet Activating Factor’), of its Enantiomer and of Some Analogous CompoundsSeveral synthetic sequences for the preparation of ‘Platelet Activating Factor’ (1a), for the corresponding enantiomeric compound (1′a) as well as for the ‘Lyso‐compounds’ (1b and 1′b) are described. The use of glycerolacetonide 2′a (from D‐Mannitol) for the preparation of 1′a and la is presented together with the synthesis of some analogues of 1′a and 1a. Structural assignment and optical purity of the compounds prepared are confirmed.
Über Pterinchemie 81. Mitteilung Die Konfiguration an C(6) von natürlichem 5,6,7,8‐Tetrahydro‐L‐biopterin und seinem Pentaacetylderivat
Authors: Prewo Roland , Bieri Jost H. , Ganguly Subhendu Narayan , Viscontini Max 
Published: December 2004

The Configuration at C(6) of Natural 5,6,7,8‐Tetrahydro‐L‐biopterin and of its PentaacetateThe structure of (6.R)‐pentaacetyl‐5,6,7,8‐tetrahydro‐L‐biopterin, one of two diastereoisomers obtained by catalytic hydrogenation and subsequent acetylation of L‐biopterin, has been determined by X‐ray diffraction analysis. The space group is P212121, a=8,053(l), b=14,955(3), c= 21,502 (4) Å. The asymmetric unit contains one molecule of the biopterin derivative and one of ethyl acetate. The R‐configuration can be assigned to C(6) by reference to the known configurations of the other asymmetric C‐atoms. As hydrolysis of this diastereoisomer yields the natural 5, 6,7,8‐tetrahydro‐L‐biopterin, the latter also possesses the (6 R)‐configuration.
Electrofugal Fragmentation of Alkylcobalamin Derivatives Using Cob(I)Alamin and Heptamethyl Cob (I)yrinate as Catalysts
Authors: Fischli Albert 
Published: December 2004

AbstractThe cob (I)alamin‐ (1(I)) and the heptamethyl cob(I)ynnate‐ (2(I)) catalyzed transformation of an epoxide to the corresponding saturated hydrocarbon 3→4→5 is examined (see Schemes 1 and 3–5). Under the reaction conditions, the epoxyalkyl acetate 3 is opened by the catalysts with formation of appropriate (b̃‐hydroxyalkyl)‐corrinoid derivatives (13, 14, 17, 18, see Schemes 12 and 14). Triggered by a transfer of electrons to the Co‐corrin‐π system, the Co, C‐bond of the intermediates is broken, generating the alkenyl acetate 4 (cf. Schemes 12 and 14) following an electrofugal fragmentation (cf. Schemes 2 and 12). The double bond of 4 is also attacked by the catalysts, leading to the corresponding alkylcorrinoids (15, 19, see Schemes 12 and 14) which in turn are reduced by electrons from metallic zinc, the electron source in the system, inducing a reductive cleavage of the Co, C‐bond with production of the saturated monoacetate 5 (see Schemes 2, 5 and 12). In the cascade of steps involved, the transfer of electrons to the intermediate alkylcorrinoids (13–15, 17–19, see Schemes 12 and 14) is shown to be rate‐limiting. Comparing the two catalytic species 1(I) and 2(I), it is shown that the ribonucleotide loop protects intermediate alkylcobalamins to some extent from an attack by electrons. The protective function of the ribonucleotide side‐chain is shown to be present in alkylcobalamins existing in the base‐on form (cf. Chap. 4 and see Scheme 14).
Note on the Synthesis of 1, 1‐Dichloro‐2, 3‐divinylcyclopropane and Other Functionalized Dichlorocyclopropanes
Authors: Müller Paul , Rey Michel 
Published: December 2004

AbstractThe title compound 1 was synthesized via addition of dichlorocarbene to dimethyl trars‐3‐hexenedioate (5), using o‐nitrophenylselenic acid‐elimination to form the double bonds. Reaction of dichlorocyclopropane 8 with ozone on silica gel furnished the monoketone 10; no diketone 11 could be isolated upon further exposure of 10 to O3/SiO2. When the bis(p‐toluenesulfonate) 13b was treated with t‐BuOK, 16 was obtained in low yield as the only isolable product. It is believed to arise from Cope‐rearrangement of an intermediate cis‐divinylcyclopropane 14 to cycloheptadiene 15, which undergoes a subsequent allylic rearrangement to 16.
Herstellung von Methylestern durch Umesterung funktionalisierter Substrate mit Titalsäureestern als Katalysatoren
Authors: Schnurrenberger Peter , Züger Max F. , Seebach Dietrich 
Published: December 2004

Synthesis of Methyl Esters by Titanate‐catalyzed TransesterificationsThe low solubility of tetramethyl titanate has so far prevented the laboratory use of titanate‐catalyzed transesterifications with formation of methyl esters. Two procedures are described here, which allow the application of this exceedingly mild method to the synthesis of methyl esters: one uses methyl propionate/Ti(OEt)4, the other one uses methanol/Gly‐Ti, a new type of catalyst, prepared from Ti(OEt)4/ethylene glycol 2:1.
Steric Effects on Reaction Rates – III. Application of Force‐Field Calculations to Chromic Acid Oxidation of Alcohols
Authors: Müller Paul , Blanc Jacky , Lenoir Dieter 
Published: December 2004

AbstractThe rates of oxidation with chromic acid of 15 bi‐ and polycyclic secondary alcohols have been measured and correlated with strain changes calculated by the MM1‐program between the alcohols and the corresponding ketones. A correlation of the same quality is obtained upon representation of OH‐strain by CH3‐strain. The significance of the correlations with respect to the oxidation mechanism as well as the limitations of the applicability of force‐field calculations to reactivity problems are discussed.
17O‐NMR. of Enriched Acetic Acid, Glycine, Glutamic Acid and Aspartic Acid in Aqueous Solution. I. Chemical Shift Studies
Authors: Gerothanassis Ioannis P. , Hunston Roger , Lauterwein Jürgen 
Published: December 2004

AbstractThe 17O‐NMR. chemical shifts of the enriched amino acids glycine, aspartic acid and glutamic acid were measured in aqueous solution as a function of pH. High magnetic fields are necessary to resolve the α, β‐ and α, γ‐carboxyl resonances of aspartic acid and glutamic acid, respectively. The chemical shifts of acetic acid were measured for comparative reasons. Ionization constants and titration shifts were obtained by nonlinear least‐squares fits to one‐proton titration curves. The average excitation energy approximation is discussed in terms of the observed changes in 17O‐shielding on deprotonation. No intramolecular association between the α‐amino group and the α‐carboxyl group in the zwitterionic form is required to explain the high‐frequency shift of the carboxylate ion. Also no indication of an intramolecular association between the α‐amino group and the side‐chain carboxyl groups of aspartic acid or glutamic acid was found.
Biosynthesis of the Indole Alkaloids. Cell‐free Systems from Catharanthus roseus Plants
Authors: Kutney James P. , Choi Lewis S. L. , Honda Toshio , Lewis Norman G. , Sato Toshitsugu , Stuart Kenneth L. , Worth Brian R. 
Published: December 2004

AbstractCell‐free systems from Catharanthus roseus plants are utilized for various studies relating to the biosynthesis of indole alkaloids. Tryptamine (5) and secologanin (6), two fundamental building units, are shown to be incorporated into the alkaloid vindoline (7). In another study, catharanthine (18) and vindoline (7) are utilized by this enzyme system and coupled to the important bisindole biointermediate 3′,4′‐anhydrovinblastineThe previously [20] used name for 17, 3′, 4′‐dehydrovinblastine, is incorrect.
(17). The latter substance is, in turn, incorporated and converted to the natural alkaloids leurosine (8), Catharine (9) and vinblastine (10), thereby providing information about the biosynthesis of these complex molecules. High pressure liquid chromatography assay of the enzymic mixture sheds light on the enzymes involved in the coupling of 18 and 7.
Synthese makrocyclischer Lactame aus Ketonen durch Ringerweiterung. Vorläufige Mitteilung
Authors: Wälchli Rudolf , Hesse Manfred 
Published: December 2004

Synthesis of Macrocyclic Lactams from Ketones by Ring Enlargement Reaction2‐Nitroalkanon 1 was converted to the N‐substituted amide 3 by condensation with acrylaldehyde followed by reductive amination. Under the analogous reaction conditions, 2‐nitrocyclododecanon (4) led to 12‐nitro‐15‐pentadecanlactam (6).
Photochemical Reduction of 2‐Bromo‐4,4‐dimethyl‐2‐cyclohexenone
Authors: Hombrecher Hermann , Margaretha Paul 
Published: December 2004

AbstractThe photochemical behaviour of 2‐Bromo‐4,4‐dimethyl‐2‐cyclohexenone (1) was studied in 2‐propanol and cyclohexane. In both solvents (n‐π*)‐excitation followed by intersystem crossing leads to population of a low‐lying triplet (T1) state, which can be quenched by 1,3‐cyclohexadiene but does not undergo chemical transformation efficiently. (π‐π*)‐Excitation affords 4,4‐dimethyl‐2‐cyclohexenone (2) as the only product. While in 2‐propanol 2 is formed in 60% from the S2‐state and in 40% from the T2‐state, in cyclohexane reduction occurs exclusively from this upper triplet state. The T2‐state can also be populated via energy transfer using acetone or benzene as sensitizer. The mechanistic dissimilarities for the reduction of excited 1 in either 2‐propanol or cyclohexane are discussed.
Nucleosides and Nucleotides. Part 19. On Detritylation with Zinc Bromide in Oligonucleotide Synthesis
Authors: Waldmeier Felix , De Bernardini Silvio , Leach Colin A. , Tamm Christoph 
Published: December 2004

AbstractZinc bromide has been shown by several groups of workers to be a useful reagent in the removal of trityl protecting groups from nucleotides. An attempt is made here to establish optimum conditions for the reaction, a strange observation is reported, and a novel workup via a soluble, lipophilic zinc complex is described.
Indolalkaloide aus Kopsia dasyrachis Ridl. 185.Mitteilung über organische Naturstoffe
Authors: Homberger Katharina , Hesse Manfred 
Published: December 2004

Indole Alkaloids of Kopsia dasyrachis Ridl.From the leaves of Kopsia dasyrachis Ridl. three new indole alkaloids, kopsidasine‐N‐oxide (1), kopsidasine (2) and kopsidasinine (3) have been isolated. Reduction of 1 with SO2 afforded 2; treatment of 2 with m‐chloroperbenzoic acid gave 1. The structure elucidation of 1 and 2, and the deternmination of their relative configurations are based mainly on the correlation of derivative 6 with the known ring skeleton of pleiocarpine (9) (Scheme 1). The structure of 3 has been established via its Hofmann degradation product 13 also prepared by treatment of 2 with CH3I (Scheme 3).
Synthese von heterocyclen. V. 1, 3, 4‐thiadiazol‐2 (3 H)‐one
Authors: Kristinsson Haukur , Winkler Tammo 
Published: December 2004

AbstractA new and highly versatile method for the synthesis of 1, 3, 4‐thiadiazol‐2 (3 H)ones 1 is described. Methoxy‐1,3,4‐thiadiazoles‐ 5, which are readily available by condensation of O‐methyl thiocarbazate (2) with acid derivatives 3, undergo an efficient cleavage to 1 and methyl chloride with hydrochloric acid in an anhydrous medium. Many new 5‐substituted thiadiazolones, unavailable by earlier routes, were synthesized. Preparative as well as mechanistic aspects are discussed. With the aid of 13C‐NMR. spectroscopy, the tautomerism of 1 was studied, and the tautomeric equilibria was shown to be dependent on the nature of the substituent in the 5‐position. The thiadiazolones 1 exist predominantly in the oxo form. The percentage of the hydroxy form, however, increases with strongly electron withdrawing substituents in the 5‐position. A good correlation with pKa− and σ‐values was observed.
Synthesen der enantiomeren Aleuriaxanthine. Nachweis eines vorherrschenden (Z)‐Aleuriaxanthins in Aleuria
Authors: Eschenmoser Walter , Uebelhart Peter , Eugster Conrad Hans 
Published: December 2004

Syntheses of the Enantiomeric Aleuriaxanthins. Detection of a Predominant (Z)‐Aleuriaxanthin in AleuriaThe enantiomeric C10‐building blocks 9 ((+)‐(2 E, 6 R)‐6, 7‐dihydroxy‐3, 7‐di methyl‐2‐octen‐l‐yl acetate) and ent‐9, and 11 ((+)‐(2 E, 6 R)‐3, 7‐dimethyl‐2, 7‐octadien‐l, 6‐diyl diacetate) and ent‐11, prepared from the optically active epoxy‐geraniols 7 and ent‐7, respectively, have been used for the syntheses of (2′ R)‐aleuriaxanthin (1) and (2′ S)‐aleuriaxanthin (ent‐1).At room temperature aleuriaxanthin exhibits no significant CD. nor ORD. However, at −180° a very distinct CD. was observed, which in the UV. range showed a surprising resemblance to that of (3 R, 3′ R)‐zeaxanthin. By direct comparison of 1 with aleuriaxanthin isolated from Aleuria aurantia [2], the (2′ R)‐chirality assigned to the latter by Liaaen‐Jensen et al. [5] is confirmed.HPLC. separation of the mixture of carotenoids from Aleuria shows the presence of a predominant (Z)‐aleuriaxanthin of yet undetermined structure.
Basicity, Lipophilicity, and Lack of Receptor Interaction of N‐Aminoalkylbenzamides and N‐Aminoalkyl‐o‐anisamides as Model Compounds of Dopamine Antagonists
Authors: Anker Lucien , Testa Bernard , Van De Waterbeemd Han , Bornand‐Crausaz Anne , Theodorou Andreas , Jenner Peter , Marsden C. David 
Published: December 2004

AbstractN‐Aminoalkylbenzamides and N‐aminoalkyl‐o‐methoxybenzamides have been prepared and examined for their pKa, log P and dopamine receptor affinity. The pKa values range from ca. 7.5 for the derivatives having a one‐C‐atom side‐chain, to ca. 10.3 for the N‐aminobutyl derivatives. These variations with chain length are satisfactoryly explained by a field model. The variations in (log P)‐values as a function of chain length and substitution at the N‐atom indicate the involvement of proximity and conformational effects. The complete inability of the compounds to displace 3H‐spiperone and 3H‐sulpiride from their specific rat striatal binding sites demonstrates the critical role of adequate aromatic substitution at positions 4 and 5.
The He(Iα) Photoelectron Spectra of Substituted 1,2‐Dithietes
Authors: Jian‐qi Wang , Mohraz Manijeh , Heilbronner Edgar , Krebs Adolf , Schütz Karin , Voss Jürgen , Köpke Brigitte 
Published: December 2004

AbstractThe He(Iα) photoelectron (PE.) spectra of a series of substituted 1,2‐dithietes have been recorded and assigned with respect to the orbital sequence derived from an STO‐3G model calculation and by correlation with the PE. spectra of related compounds. The results provide additional support for the presence of a closed, four‐membered ring moiety in all the 1,2‐dithietes investigated. In all cases the two highest occupied molecular orbitals are b2(π)= HOMO, a2(π), with exception of 3,4‐bis(trifluoromethyl)‐1,2‐dithiete where the sequence b2(π), a2(π) or a2(π), b2(π) is uncertain.
Metal complexes with macrocyclic ligands, XVII. Synthesis of two key intermediates for the preparation of mono‐N‐functionalized tetraazamacrocycles and their metal complexes
Authors: Hediger Markus , Kaden Thomas A. 
Published: December 2004

AbstractWith a modification of the cyclization procedure of Richman & Atkins [8] the two macrocycles 1,4,7‐tritosyl‐11‐benzyl‐1,4,7,11‐tetraazacyclotetradecane (8) and 1,7,11‐tritosyl‐4‐trityl‐1,4,7,11‐tetraazacyclotetradecane (15) were prepared. After selective cleavage of the benzyl and trityl group, respectively, one obtains the two key products 1,4,7‐tritosyl‐11‐benzyl‐1,4,7,11‐tetraazacyclotetradecane (9) and 1,7,11‐tritosyl‐4‐trityl‐1,4,7,11‐tetraazacyclotetradecane (16) which have three N‐atoms protected by tosyl groups and one accessible for further reactions.To test some of the possibilities we have alkylated 9 and 16 with iodoacetamide, 1‐tosyl‐aziridine and acrylonitrile. After detosylation with HBr in glacial acetic acid in the presence of phenol mono‐N‐functionalized tetraazamacrocycles were thus obtained. The advantage of this synthesis is that the cyclization which is the most difficult step of the whole procedure, has to be done only once, regardless of the nature of the pendant arm. In addition a large number of derivatives can be prepared by varying the alkylation component.With Ni2+, Cu2+ and Zn2+ metal complexes of these new ligands were prepared and their IR. and VIS. spectra studied. In the case of the carbamoyl derivatives 12, 14 and 18 the Cu2+‐complexes exist in two forms. Whereas at low pH the carboxamide group of the pendant arm is probably not bound to the metal ion, at high pH after deprotonation it coordinates in one of the axial positions.
Versuche zur Herstellung eines «Bis(triasterans)» und Synthese des heterocyclischen (Tricyclo[4.4.1.01,6]undeca‐3,8‐dien‐11,11‐dimethyl)sulfits
Authors: Neidlein Richard , Wesch Karl Friedrich 
Published: December 2004

Tentative Synthesis of ‘Bis(triasterane)’ and Synthesis of the Heterocyclic (Tricyclo[4.4.1.01,6]undeca‐3,8‐diene‐11,11‐dimethyl)sulfiteThe synthesis of the bis(triasterane) (1) has been tried; the reaction of ‘isotetraline’ (1,4,5,8‐Tetrahydronaphthalene; 2) with diazomalonate yielded the tricyclic systems 5 and 6, and not 4. Hydrolysis of 5 gave the monocarboxylic acid 7, and not the dicarboxylic acid 9. The latter could be obtained from the dibromoderivative 8, but 9 couldn't be converted to the acyl chloride 10. The reduction of 9 with LiAlH4 yielded the crystalline diol 11, which was cyclized with SOCl2 to the heterocycle 12. The spectral data of the new compounds 5, 6, 7, 11 and 12 are reported and discussed.