Technische Verfahren zur Synthese von Carotinoiden und verwandten Verbindungen aus 6-Oxo-isophoron. V. Synthese von Astacin

Technical Procedure for the synthesis of Carotenoids and Related Compounds from 6-Oxo-isophorone

1 Teil 4 dieser Reihe: [1].

. V. Synthesis of Astacene Starting from optically inactive astaxanthin intermediates, the highly oxygenated carotenoid astacene was synthesized in seven steps (55% overall yield from 6-oxo-isophorone). Key features of the new approach are base- and acid-catalyzed rearrangements of acetylenic intermediates such as those described in Schemes 2, 7 and 8.     

Synthese optisch aktiver Nickel-Komplexe mit porphinoidem Ligandsystem

Synthesis of Optically Active Porphine-type Nickel Complexes Both enantiomers of [1-methyl-8 H-HDP]nickel-perchlorate

1 For nomenclature see footnote 5 in this paper.

( 2a and 2b , respectively) have been synthesized by the following reaction sequence: (a) base induced addition of (?)-( R )-2-octanol to 1 , (b) separation of the two diastereomeric monoadducts 4a and 4b , (c) reaction with methyl magnesium iodide containing an excess of methyl iodide, (d) acid induced elimination of 2-octanol from the diadducts 6a and 6b . By a similar procedure both enantiomers of [1-butyl-8 H-HDP] nickel-perchlorate ( 3a and 3b , respectively) have been prepared. The reaction of 3a with butyl lithium yields in a kinetically controlled addition predominantly the optically active cis -1, 11-dibutyl adduct 8 and in minor quantity the meso - cis -1, 11-dibutyl adduct 9 .     

Halochrome Molekeln. Synthese und acidobasisches Verhalten substituierter 3′,6′-Bis (dimethylamino)-spiro [5H-imidazo [2, 1-α]-isoindolin-5,9′-xanthene]

Halochromic Molecules. Synthesis and Acidobasic Behaviour of Substituted 3′,6′-Bis(dimethylamino)-spiro [5H-imidazo [2,1-α]isoindolin-5,9′-xanthenes] Substituted 3′,6′-Bis (dimethylamino)-spiro [5H-imidazo [2, 1-α]isoindolin-5,9′-xanthenes] are prepared and their ¹H-NMR. spectra are discussed. An investigation of the complex protonation equilibria is made by stopped flow kinetic and spectrophotometric methods. pK values are determined and the results are discussed.     

The He(Iα) Photoelectron Spectra of the Perfluoroderivatives of Trisannelated Benzenes and Tetrakisannelated Cyclooctatetraenes

The He(Iα) photoelectron (PE) spectra of tris(perfluorocyclobuta)benzene 4 (F)

1 3,3,4,4,7,7,8,8,11,11,12,12-Dodecafluorotetracyclo[8.2.0.0^2,5.0^6,9]dodeca-1,5,9-triene

, tris(perfluorocyclopenta)benzene 5 (F)

2 1,1,2,2,3,3,4,4,5,5,6,6,7,7,8,8,9,9-Octadecafluoro-2,3,4,5,6,7,8,9-octahydro-1H-trindene.

, tetrakis(perfluorocyclobuta)cyclooctatetraene 6 (F)

3 3,3,4,4,7,7,8,8,11,1l,l2,l2,l5,15,16,16-Hexadecafluoropentacyclo[12.2.0.0^2,5.0^6,9.0^10,13]hexadeca-1,5,9,13-tetraene.

, and of tetrakis(perfluorocyclopenta)cyclooctatetraene 7 (F)

4 1,1,2,2,3,3,4,4,5,5,6,6,7,7,8,8,9,9,10,10,11,11,12,12-Tetracosafluoro-1,2,3,4,5,6,7,8,9,10,11,12-dodeca-hydrotetracyclopenta[a,c,e,g]cyclooctene.

are reported. A tentative assignment of the PE spectra is derived by empirical correlation with those of relevant reference compounds. The results suggest that 6 (F) retains the D_4h-conformation in the gas phase, i.e. A conformation with a planar cyclooctatetraene ring, as observed in the crystal. All four compounds exhibit a sharp increase of their first ionization energies, relative to the corresponding parent hydrocarbons, due to the perfluoro effect.     

1H-NMR.-spektroskopische Bestimmung der Enantiomerenreinheit von Allencarbonsäureestern mit optisch aktiven Europium-Verschiebungsreagenzien

¹H-NMR. Spectroscopic Determination of Enantiomeric Purities of Allenic Esters Using Optically Active Europium Shift Reagents The racemic allenic methyl esters 3--7 and the racemic allenic diesters 8--10 (cf. Scheme 2) in 1,1,2-trichloro-1,2,2-trifluoroethane (TCFE) and CCl₄ in the presence of optically active tris[3-(heptafluorobutyryl)-(+)-camphorato]europium(III) (Eu(hfc)₃) have induced unlike ¹H-NMR. shift differences (ΔΔδ) for the protons of the methoxycarbonyl groups of their enantiomers. In some allenic esters the shift reagent causes additional separation of resonance signals; thus, further substituents on the allenic framework may be differentiated in the racemic mixture. This finding provides a widely applicable method for the determination of absolute enantiomeric purities of allenic esters and their corresponding acids. Accordingly we found for optically pure (+)-(S)-2-methyl-2,3-pentadienoic acid ((+)-(S)- 13 ; cf. Fig. 2) a calculated [α] value of + 73.3 ± 1.8°. Finally, the substituent effects on ΔΔδ-values (cf. Table 1--3) are discussed.     

Synthese und 1H-NMR-Analyse von Triafulvalen-Vorstufen

Synthesis and ¹ H-NMR Analysis of Triafulvalene Precursors . An attractive concept for the synthesis of triafulvalene ( 1 ) by retro-Diels-Alder reaction (RDA reaction) of precursors 4 and 5 is presented. Both precursors are available in two steps by dibromocarbene addition to dibenzobarrelene ( 8 → 9 ) and barrelene ( 10 → 11 ), followed by CuCl₂-induced formal `carbene dimerization' ( 9 → 4 and 11 → 5 , respectively). Thermal-fragmentation experiments of triafulvalene precursor 4 were unsuccessful, mainly due to the very low volatility of 4 . Spectral parameters of the complex ¹H-NMR spectrum of 3,3′-bi(tricyclo[3,2,2,0^2,4]nona-6,8-dienylidene) ( 5 ) have been determined by analysis of subspectra generated by selective H,H-decoupling experiments followed by iteration/simulation sequences.     

Synthese von 1-Aryl-2-azido-2-alken-1-onen

Zusammenfassung Durch Kondensation von -Azidoacetophenonen mit aliphatischen Aldehyden wurden 1-Aryl-2-azido-2-alken-1-one erhalten. Die Thermolyse dieser Verbindungen gab Azirine, die sich mit Cyclopentadien in 2-Azatricyclo[3.2.1.0^2.4]-6-octene überführen lassen.

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Synthesis of 1-aryl-2-azido-2-alken-1-ones (ene-azides, V)

1-Aryl-2-azido-2-alken-1-ones were obtained by condensing -azidoacetophenones with aliphatic aldehydes. Thermolysis of these compounds gave azirines, which can be converted to 2-azatricyclo[3.2.1.0^2.4]-6-octenes by reaction with cyclopentadiene.

     

Zur Zersetzung von Tetrathiowolframaten und Bildung von Nonathiotriwolframaten

Decomposition of Tetrathiotungstates and Formation of Nonathiotritungstates The tetrathiotungstates have been prepared by reaction of [NH₄]₂WS₄ with [R₄X]Y (Y = OH, Cl or I). The tetrathiotungstates decompose under variable conditions to form [R₄X]₂W₃S₉. The thiotungstates [R₄X]₂WS₄ and [R₄X]₂W₃S₉ have been characterized by chemical and thermoanalytical methods as well as by infrared, electron absorption, ¹H-NMR, and mass spectra. The decomposition of [R₄N]₂WS₄ has been studied kinetically. A mechanism of the formation of W₃S₉^2? is suggested.     

Zum Mechanismus der α-Alkinon-Cyclisierung: Synthese und Thermolyse von 1-(1-Methylcyclopentyl)[3-13C]prop-2-inon

On the Mechanism of the α-Alkynone Cyclization: Synthesis and Thermolysis of 1-(1-Methylcyclopentyl)[3-¹³C]prop-2-ynone The relative migratory aptitude of two acetylenic substituents in the α-alkynone cyclization, a thermal conversion of α-acetylenic ketones A to 2-cyclopentenones C , was investigated by isotope-labeling experiments. The α-alkynone [β-¹³C]- 1 , specifically labeled with ¹³C at the β-acetylenic C-atom C(3), was synthesized by an intramolecular Witting reaction (230–300°) of the diacylmethylidenephosphorane [¹³C]- 7. The latter resulted from acylation of methylidenetriphenylphosphorane with the acid chloride 4 to yield the acylmethylidenephosphorane 5 , which in turn was formylated with acetic [¹³C]formic anhydride ([¹³C]- 6. ) Upon thermolysis of [β-¹³C]- 1 , its label at C(β) was transferred almost exclusively to C(β) of the 2-cyclopentenone moiety in the resulting cyclization product [¹³C]- 2. We conclude that there is a distinct preference for hydrogen migration in the acetylene → alkylidene carbene isomerization (A → B) which precedes the cyclization step (B → C). No evidence was found for a fast reversibility of this isomerization (A ? B) involving both acetylenic substituents.     

Zur oxidativen Addition von 1-Halogenalk-1-inen – Synthese und Struktur von Phenylalkinylpalladium-Komplexen

On the Oxidative Addition of 1-Halogenalk-1-ynes – Synthesis and Structure of Phenylalkynylpalladium Complexes [Pd(PPh₃)₄] ( 2 ) reacts with IC≡CPh and ClC≡CPh in the sense of an oxidative addition to give trans-[Pd(C≡CPh)X(PPh₃)₂] (X = I: 3 a , X = Cl: 3 b ). As side products trans-[PdX₂(PPh₃)₂] (X = I: 4 a , X = Cl: 4 b ; < 10%) and PhC≡C–C≡CPh ( 5 ; X = I: ca 30%, X = Cl: < 4%) are formed. 3 a and 3 b were characterized by NMR (¹H, ¹³C, ³¹P) and IR spectroscopies as well as by X-ray single-crystal structure analyses. In the crystals of 3 a and 3 b isolated molecules were found. The Pd–C≡C–Ph unit is linear in 3 a and approximately linear in 3 b [Pd–C≡C 174.2(6)°, C≡C–C 179,0(7)°].     

Rhodium (I)-katalysierte Reaktionen der [2+4]-Cycloaddukte aus 3,4-Dimethoxyfuran und Acetylendicarbonsäure-estern

[2+4]-Cycloaddition Products of 3,4-Dimethoxyfuran with Acetylenedicarboxylates and Their Transformations under the Influence of Rhodium(I) Catalysts 3,4-Dimethoxyfuran ( 1 ) readily reacts with acetylenedicarboxylates ( 2 ) at room temperature in a [2+4]-cycloaddition to give a mono-( 3 ) and several di-addition products. 90% of the latter consists of the endo-exo compound 4 . Under the influence of catalytic amounts of [Rh(CO)₂Cl]₂ the mixture of mono- and di-adducts in methanolic solution is smoothly transformed into endo-5,5,6-trimethoxy-7-oxabicyclo [2.2.1]hept-2-ene-2,3-dicarboxylate

1 Alle Verbindungen sind racemisch. Die Formeln stellen jeweils nur ein Enantiomeres dar.

(5) , 3-hydroxy-4,5-dimethoxyphthalate ( 6 ) and (I R *, 2 S *, 4 R *, 5 R *, 7 R *, 11 R *, 12 R *) -5,8,8,9,12-pentamethoxy-3,6-dioxatetracyclo [5.3.1.1 ^2,5 . 0 ^4,11 ]dodec-9-ene-1,11-dicarboxylate ( 7 ).     

Isolierung,Struktur und Synthese des Metaboliten von Azapropazon-dihydrat

The renal excretion of AZAPROPAZONE-DIHYDRATE (X)

1 Handelsname: PROLIXAN®. Hersteller: Siegfried AG, Zofingen.

by humans was investigated. Following oral administration a new substance was detected in the urine besides X by TLC. Both compounds were separated by preparative layer chromatography and shown to be unchanged X and its hydroxylated metabolite VIII. The structure of VIII was established by chemical and spectroscopic methods (IR., NMR.) and confirmed by synthesis (Scheme 1).     

Chemie von α-Aminonitrilen. 12. Mitteilung. Sondierungen über thermische Umwandlungen von α-Aminonitrilen

Chemistry of α-Amino Nitriles

1 11. Mitteilung: [1].

. Exploratory Experiments on Thermal Reactions of α-Amino Nitriles The paper extends a previously published report [4] on chemical properties of α-amino nitriles and of members of the C₃H₄N₂ ensemble (Scheme 1) as observed in experiments carried out under non-aqueous conditions. The reactions investigated and the observations made are summarized in some detail in the English footnotes (*) referring to Schemes 1–17 and Fig. 1.     

Cycloadditionsreaktionen von Trifluormethylisocyanid an Diphosphene. Synthese und Struktur des neuartigen 2-Phosphiniden-1, 3-azaphospholidins

Cycloaddition Reactions of Trifluoromethyl Isocyanide with Diphosphenes. Synthesis and Structure of the new 2-Phosphinidene-1,3-azaphospholidine Derivative [2 + 1] Cycloaddition reactions of trifluoromethyl isocyanide 1 and methylisocyanide 2 with the diphosphene R? P?P? R 3a ( a R ? C[Si(CH₃)₃]₃) yield the three membered heterocyclic diphosphirane imines 4 and 5 , respectively. Whereas the trifluoromethyl substituted compound 4 is thermally very stable, the methylsubstitued derivative 5 slowly looses methyl isocyanide reforming the diphosphene 3a . In the reaction of 1 with R? P?P? R 3b [ b R = 2,4,6-(t-Bu)₃C₆H₂] no evidence for the formation of a three membered ring compound could be obtained. The five membered heterocycle 3-(2,4,6-Tri-t-butylphenyl)-2-[2,4,6-tri-t-butylphenyl)-phosphinidene]-1-trifluoromethyl-4, 5-bis(trifluoromethylimin)-1,3-azaphospholidine 6 was isolated as the only product together with unreacted 3b . The structure of 6 , triclinic, P1 , a = 1081.1(8), b = 1463.1(11), c = 1643.6(5)pm, α = 64.01(6), β = 81.22(4), γ = 74.04(5)°, Z = 2, R = 0.080, R_w = 0.085, has been elucidated by X-ray diffraction.     

Synthese und Eigenschaften von Bis-[dialkylamino-methylarsino]-methanen

Synthesis and Properties of Bis-[dialkylamino-methyl-arsino]-methanes The reactions of methan-bis-[methyl-chlorarsine] H₂C[As(CH₃)Cl]₂ with secondary amines lead to the formation of bis-[dialkylamino-methylarsino]methanes H₂C[As(CH₃)NR₂]₂. The cleavage of the As? N bond with acid molecules HX (X?OH, OR, SR, NR₂, halogen) results in the formation of the compounds H₂C[As(CH₃)X]₂. The IR and ¹H-NMR spectra are discussed and presented.     

Stereochemistry of the Platinum Catalyzed Hydroformylation of Olefins

The deuterioformylation of (Z)- or (E)-2-butene catalyzed by [DIOP]Pt(SnCl₃)-Cl

1 DIOP=2,3-O-isopropylidene-2,3-dihydroxy-1,4-bis(diphenylphosphino)butane.

gives predominantly erythro- or threo-1,3-[²H]₂-2-methylbutanal respectively. Hence, hydroformylation by this catalytic system must take place with cis-stereochemistry.     

Steric Rate-Retardation in the Chromium Trioxide Oxidation of 4,6-Dimethyl-benzocyclobutenol

The rate of oxidation of 4, 6-dimethyl-benzocyclobutenol

1 This nomenclature is preferred in the literature [1] [2] to the more systematic name (7-hydroxy-3, 5-dimethyl-bicyclo [4.2.0] octa-1,3,5-triene).

( 1 ) with chromium trioxide has been measured. After correction for the influence of the two methyl substituents the rate of oxidation of 1 is lower than that of 1-tetralol ( 9 ) and 1-indanol ( 10 ) by factors of 3 and 5 respectively. The lower oxidation rate of 1 as compared to 9 and 10 is interpreted in terms of a steric rate retardation arising from angle strain in the developing carbonyl function of 4, 6-dimethylbenzocyclobutenone ( 4 ).     

Die stereospezifische Reduktion von (1R)-3-endo-Aminocampher zu (1R)-3-endo-Aminoborneol

The highly stereospecific reduction of (1R)-3-endo-aminobornan-2-one ( 2 ) to [1R]-3-endo-amino-2-endom-bornanol ( 1 ) is described. This reaction is achieved by using alkylaluminumdichlorides, a new group of reducing agents for the reduction of the ketone 2 to the secondary alcohol 1

1 Diesc Reduktion ist Gegenstand van Patcntanmeldungen, z. B. [l].

     

Zur Photochemie von (Z,Z)-2,7-Cyclodecadien-1-on und 4,8-Cyclododecadien-1-on. Synthese und Eigenschaften von Tricyclo[5.3.0.02,8]decan-Systemen

On the Photochemistry of (Z,Z)-2,7-Cyclodecadien-1-one and 4,8-Cyclododecadien-1-one. Synthesis and Properties of Tricyclo[5.3.0.0^2,8]decane Systems Irradiation of (Z,Z)-2,7-cyclodecadien-1-one ( 3 ) yields (Z,Z)-3,7-cyclodecadien-1-one ( 12 ) or tricyclo-[5.3.0.0^2,8]decan-4-one ( 16 ), depending on the reaction conditions. Irradiation of 4,8-cyclododecadien-1-one ( 28 ) results also in a light-induced transannular [2 + 2] cycloaddition, yielding tetracyclo[7.3.0.0^2,100^3,6]dodecan-1-one ( 30 ). Starting from 16 , the preparation of tricyclo[5.3.0.0^2,8]dec-4-ene ( 19 ), tricyclo[5.3.0.0^2,8]dec-4-ene ( 21 ) and tricyclo[5.3.0.0^2,8]deca-3,5-diene ( 24 ) is described. The ¹H-NMR and ¹³C? NMR spectra of the newly prepared compounds are discussed. In the case of 19, 21 , and 24 , the electronic structure is discussed on hand of their PE spectra.     

Regioselectivity of the Diels-Alder Additions of 2-Substituted 5,6 Dimethylidenenorbornanes and-bicyclo[2.2.2]octanes

The cycloadditions of methyl propynoate and methyl vinyl ketone to 5,6-dimethylidene-2-norbornanone ( 6 ) are para′-regioselective

1 “Para” (p) designs in this paper the 4, 9-disubstituted tricclo[6.2.1.0^{2, 7}] undecane- and 4, 9-disubsstituted tricycle[6.2.20^2,7] dodecane derivatives, “meta” (m) design the corresponding 4, 10-disubstituted compounds.

. A smaller para -regioselectivity is observed for the addition of methyl propynoate to 5,6-dimethylidene-2bicyclo[2.2.2]octanone ( 10 ). No regioselectivity is observed with 5,6-dimethylidene-2exo-norbornyl alcohol ( 3 ), acetate ( 5 ) and 5,6-dimethylidene-2exo-bicyclo[2.2.2]octanol ( 9 ). PMO arguments based on the shape of the HOMO's and subHOMO's of the dienes allow to rationalize these observations. Unpredictable para′- or ‘meta’regioselectivities are found for the Diels,-Alder additions of 5,6-dimethylidene-2endo-norbornyl alcohol ( 2 ), acetate ( 4 ) and 5,6-dimethylidene-2endo-bicyclo[2.2.2]octanol ( 8 ). The carbonyl group of β,γ unsaturated ketones such as 6 and 10 can act as an electron donating homoconjugated substituent. The n(CO) ? σ[C(1), C(2)] ? π[C(5), C(6)] hyperconjugative interaction can override the usual electron-withdrawing effect of this function.