Enamides via Long‐Distance Migration of Double Bonds

A new method for preparation of enamides (N‐(alken‐1‐yl) amides) by means of the ‘long‐distance' migration of the double bond in unsaturated amides in the presence of [Fe(CO)₅] is described. The method is shown to be particularly useful for the isomerization of N‐(but‐3‐enyl)amides, while, in the case of N‐(pent‐4‐enyl) and N‐(hex‐5‐enyl) amides the mixture of products was formed and the yield of the enamide was relatively low.     

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.     

Thermische Reaktionen im Massenspektrometer Modellreaktionen zur Untersuchung thermischer Umalkylierungen. 11. Mitteilung über das massenspektrometrische Verhalten von Stickstoffverbindungen

During the introduction of an organic compound into the mass spectrometer thermal reactions can take place before the ionisation process, thus changing the structure of the compound. On the basis of known experimental results the following reactions, which are independent of electron bombardment are discussed: decarboxylation, dehydration, loss of alcohols, decarbonylation, decomposition of carboxylic esters, retro aldol reaction and similar processes, retro DIELS -ALDER reaction, isomerisation, disproportionation, hydrogenolysis-dehydrogenolysis, transalkylation, dimerisation, and pyrolysis of quaternary nitrogen containing compounds. Finally, the results of novel model reactions concerning thermal transalkylation are discussed.     

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.     

Über das Alkaloid Lonicerin aus Callichilia barteri. 137. Mitteilung über Alkaloide

The alkaloid lonicerine was isolated from Callichilia barteri (Apocynaceae). By chemical and spectroscopic evidence it could be shown to be 16-epi-aspidodasycarpine ( 1 ).     

Synthesis of 12-Methyl-13-tridecanolide

The title compound was prepared from 2-nitrocyclodecanone ( 2 ). Compound 2 was treated with 2-methylpro-penal to give the Michael-addition product 3 which was reduced to the alcohol 5 and the latter ring-enlarged with Bu₄NF to 12-methyl-10-nitro-13-tridecanolide ( 6 ) followed by reductive elimination of the NO₂ group by Bu₃SnH.     

Zur Bestimmung der in der Luft enthaltenen Mikroorganismen

Ohne Zusammenfassung