Über die Bildung cyclischer Ionen und bicylischer Übergangszustände beim Zerfall substituierter α,ω-Alkandiamine im Massenspektrometer. 23. Mitteilung über das massenspektrometrische Verhalten von Stickstoffverbindungen

Formation of cyclic ions and bicyclic transition states in the mass spectral decomposition of substituted α,ω-alkanediamines. N-Phenethyl-N(4-acetamidobutyl)-p-toluene-sulfonamide ( 4 ) and its homologues were synthesized and the mass spectral behaviour investigated. After loss of a benzyl radical from the molecular ion two different fragmentation reactions are observed. The lower homologous members – namely compounds 1 , 2 and 3 – lose ketene by formation of cyclic ions (Scheme 1). The higher homologues of this series of compounds ( 4 , 5 , 6 ) show a pronounced (to 18% ∑₅₀) loss of p-toluene sulfonic acid. This decomposition reaction proceeds presumably through a bicyclic transition state (Scheme 3).     

Beitrag zur massenspektrometrischen retro-Diels-Alder-Reaktion: 1,2,3,4-Tetrahydrophenanthren. 35. Mitteilung über massenspektrometrische Untersuchungen

Contribution to the Mass Spectral retro-Diels-Alder Reaction: 1,2,3,4-Tetrahydrophenanthrene [1,4-¹³C]-1,2,3,4-Tetrahydrophenanthrene (1) was synthesized starting from [1,4-¹³C]-succinic acid. The mass spectral behavior (EI./MS., 70eV) of 1 is very similar to that of tetraline [2] concerning its loss of ethylene from the molecular ion. Similarly the fragmentation reaction of the synthetic precursors, ketones 7 and 8 , seems to partly undergo a carbon rearrangement reaction prior to the elimination of ethylene which is unlike to the behavior of α-tetralone.     

Neuartige massenspektrometrische Zerfallsreaktionen bei α,ω-disubstituierten Alkanen. 15. Mitteilung über das massenspektrometrische verhalten von stickstoffverbindungen [1]

The mass spectral behaviour of α,ω-disubstituted alkanes and, especially, that of different N-substituted α,ω-diaminoalkanes has been investigated. It was found that the two amino groups which are separated by CH₂-groups can fragment only to a small extent indepently from each other. Yet those fragmentation reactions are predominant in which both functional groups participate. The main reactions of this type are:

• 1 Loss of the N-substituent (R) from the molecular ion, leading to the [M⁺—R]-ions.
• 2 Loss of NH₃, primary or secondary amines from the [M⁺—R]-ion in the case of monodi-, tri- and tetra-substituted diamino compounds respectively.
• 3 α-Cleavage to the non charged nitrogen atom by forming the ions
• 4 S_Ni-type fragmentation.

The mechanisms of these fragmentation patterns were deduced by using D-labelled derivatives, from metastabile peaks and high resolution mass spectrometry. These reactions seem to be typical for disubstituted alkanes.     

Ammoniakverlust aus α,ω-Alkandiaminen im Massenspektrometer. 22. Mitteilung über das massenspektrometrische Verhalten von Stickstoffverbindungen

Loss of ammonia from α,ω-alkanediamines in the mass spectrometer . Under electron impact α,ω-alkanediamines lose ammonia from the molecular ion. This fragmentation reaction is explained in the case of 1.4-butanediamine ( 1 ) on the basis of the spectra of homologues and deuteriated derivatives. The reaction proceeds via neighbouring group participation; the mechanism is given in Scheme 1.     

Die massenspektrometrische Retro-Diels-Alder-Reaktion: 1,2,3,4-Tetrahydrocarbazol. 30. Mitteilung über massenspektrometrische Untersuchungen

The mass spectral retro Diels-Alder-reaction: 1,2,3,4-tetrahydrocarbazole 1,2,3,4-Tetrahydrocarbazole undergoes a retro Diels-Alder-reaction under electron impact. C(2) and C(3) are eliminated as ethylene. This is shown by measuring the deuterated derivatives 1a , 1b and 1c . Furthermore the oxo-1,2,3,4-tetrahydrocarbazole derivatives 3 and 4 are investigated in respect to the mass spectral retro Diels-Alder reaction too.     

Substituenteneinfluss bei der massenspektrometrischen Fragmentierung: Untersuchungen an N-methyl-β,β′-diphenyl-diäthylaminen. 19. Mitteilung über das massenspektrometrische Verhalten von Stickstoffverbindungen

Some different substituted N-methyl-β,β′-diphenyl-diethylamines (I) were investigated mass spectrometrically. The main fragmentations and their genesis are summarized in Scheme 2. The molecular ion generates the major fragmentions a (m/e 148) and b (m/e (147 + X)); c (m/e 105) is formed from a and d (m/e (104+X)) from b by further decomposition. The logarithms of the ratios of the relative ion intensities a/b , c/a and d/b were correlated according to the Hammett equation with different substituent constants. The following correlation coefficients (at 20ev) were found: r = 0,98 (σ⁺), r = 0,63 (σ) and r = 0,96 (σ) respectively. On the basis of the above Hammett correlations, the value of this kind of investigation for the elucidation of mass spectral fragmentation mechanisms is discussed.     

9-Methyl-cis-decalin-1,3-dion: Stereochemische Untersuchungen an 9-Methyl-cis-decalin-Derivaten. 5. Mitteilung über cyclische β-Diketone

The synthesis and the spectral properties of the hitherto unknown 9-methyl-cis-decalin-1,3-dione ( 16 ) are described. The keto-enol equilibrium of 16 in various solvents was determined by NMR. spectroscopy. The configuration and conformation of a large number of intermediates and derivatives were determined.     

Methode zur Konstitutionsaufklärung von Celluloseformalen von niedrigem Substitutionsgrad. 29. Mitteilung über textilchemische Untersuchungen

A method is described which allows the determination of the hydroxyl group(s) in glucose units of cellulose which react with formaldehyde at low degrees of substitution (0.2 to 1.5% CH₂O on cellulose). It consists of permethylation of the cellulose by a sequence of two methylations with dimethylsulfate and NaOH (without solvent) followed by 2 exchange methylations with methyl iodide and sodium n-butoxide and further steps described earlier [2]. The results demonstrate that the use of the new permethylation method leads to a loss of material of less than 5%.     

Nachbargruppeneffekte bei der massenspektrometrischen Fragmentierung: N-Acetyl-ω-Phenylalkylamine. 20. Mitteilung über das massenspektrometrische verhalten von stickstoffverbindung

The mass spectral behaviour of the difunctional alkane N-acetyl-4-phenyl-butylamine ( 3 ) was investigated. The main fragmentation of compound 3 is caused by the interaction on the two functional groups, which could be shown by comparison of the corresponding monofunctional compounds n-butylbenzene ( 4 ) and N-acetyl-n-butylamine ( 5 ). On the bases of high resolution data, the analyses of metastable transitions and the comparison of the spectra of some homologs and deuterated analogs of 3 the structures and their genesis of the main fragment i ons were deducted.     

Photochemie von tricyclischen β, γ-γ′, δ′-ungesättigten Ketonen. 50. Mitteilung über Photoreaktionen

Photochemistry of tricyclic β, γ-γ′, δ′-unsaturated ketones The easily available tricyclic ketone 1 (cf. Scheme 1) with a homotwistane skeleton yielded upon direct irradiation the cyclobutanone derivative 3 by a 1,3-acyl shift. Further irradiation converted 3 into the tricyclic hydrocarbon 4 . However, acetone sensitized irradiation of 1 gave the tetracyclic ketone 5 by an oxa-di-π-methane rearrangement. Again with acetone as a sensitizer the ketone 5 was quantitatively converted to the pentacyclic ketone 6 . The conversion 5 → 6 represents a novel photochemical 1,4-acyl shift. The possible mechanisms are discussed (see Scheme 7). The tricyclic ketone 2 underwent similar types of photoreactions as 1 (Scheme 2). Unlike 5 the tetracyclic ketone 9 did not undergo a photochemical 1,4-acyl shift. The epoxides 10 and 14 derived from the ketones 1 and 2 , respectively, underwent a 1,3-acyl shift upon irradiation followed by decarbonylation, and the oxa-di-π-methane rearrangement (Schemes 3 and 4). The diketone 18 derived from 1 behaved in the same way (Scheme 5). The tetracyclic diketone 21 cyclized very easily to the internal aldol product 22 under the influence of traces of base (Scheme 5). Upon irradiation the γ, δ-unsaturated ketone 24 underwent only the Norrish type I cleavage to yield the aldehyde 25 (Scheme 6).     

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.     

α,ω-Dihydroxyalkan-α,α-diphosphonsäuren durch Desaminierung von ω-Aminoalkandiphosphonsäuren

α,ω-Dihydroxyalkane-α,α-diphosphonic Acids by Desamination of ω-Aminoalkanediphosphonic Acids The title compounds represent a new group of complexing diphosphonic acids which are synthesized by desamination of ω-amino-α-hydroxyalkane-α,α-diphosphonic acids. In case of α,ω-dihydroxypropane-α,α-diphosphonic acid ( 1 ) a phosphonylated phostone is formed by dehydration. In contrast, the ω-phenyl drivative of ( 1 ) yields in a smooth reaction under the same conditions 2-hydroxy-5-phenyl-3-phosphono-1.2-oxaphosphol-3-en-2-oxide ( 6 ).     

Photochemische Reaktionen. 112. Mitteilung [1] Zur Photochemie α, β-ungesättigter γ, δ-Epoxyester. III. Ergänzende Untersuchungen zur Triplettreaktivität

On triplet sensitization (E)- 5 gives (Z)- 5 and isomerizes via C(δ), O-bond cleavage to the cyclobutanone 6 and the conjugated γ-ketoester 7 . - On singulet excitation 6 undergoes decarbonylation and yields the bicyclo [4.1.0]heptane 8 . However, on triplet sensitization 6 is converted to the isomeric tricyclononane 9 by a stereospecific oxa-di-π-methane rearrangement. The structure of 9 is determined by X-ray analysis of the p-nitrobenzoate 15: a = 10.573, b = 14.707, c = 13.494 Å, β = 112.40°, P2₁/n, Z, = 4.     

Über 9β,10α-Steroide. 4. Mitteilung [1]. Strukturaufklärung von mikrobiologischen Umsetzungsprodukten

The structure and the stereochemistry of some 8- and 9-hydroxy-9β, 10° (retro)-steroids of the androstane and pregnane series, obtained microbiologically, have been elucidated.     

Dampfdruckmessungen und massenspektrometrische Untersuchungen der Gasphase über Erdalkalimetallhalogeniden

Vapor Pressure and Mass Spectrometrical Measurements of Gaseous Phase of Alkaline Earth Halides Vapor pressures and vapor compositions of molten alkaline earth halides were measured by Knudsen effusion method and mass spectrometry, respectively. The enthalpies of dissociation of strontium and barium halides were calculated from appearance potentials of alkaline earth ions M′⁺. Temperature dependence of vapor pressure and enthalpies of vaporization are given. The vapor over molten alkaline earth halides contains only small amounts (max. 1.9%) of dimeric molecules.