A. I. Ermakov

The structure of alatol

SummaryFrom the roots ofPrangos alata Grossh (Prangos biebersteinii Karjag) a new furocoumarin (I), C17H18O6, mp 125–127°C (from benzene), which has been called alatol, has been isolated.On the basis of the results of IR and NMR spectra and chemical properties, the structure of 5-(2″-hydroxy-3″-methoxy-3″-methylbutoxy)-furo-2′,3′:7,6-coumarin has been proposed for (I). This structure has been confirmed by the partial synthesis and by the mass spectra of alatol and of its acetate.

The structure of ulopterol

ConclusionsA new coumarin C15H18O5 with mp 141.5–142.5° C (from benzene) has been isolated from the roots and fruit ofPrangos uloptera D. C., and it has been called “ulopterol.” On the basis of UV, IR, NMR, and mass spectra it has been found to have the structure of 6-(2′,3′-dihydroxy-3′-methylbutyl)-7-methoxy-coumarin and is a geometrical isomer of meranzin hydrate.

Mass spectra of substituted piperidines

The mass spectra of piperidines and N-methylpiperidines with various functional groups attached to the heteroring carbon atoms were studied. The mechanisms of the formation and fragmentation of the amine fragments with various structures and specific hydrogen and skeletal rearrangements are discussed. It is shown that the sequence of cleavage of the heteroring bonds depends on the properties of the substituents and their positions in the ring.

Gosferol — A new furocoumarin from the roots of Prangos ferulacea

SummaryFrom the roots ofPrangos ferulacea (L.) Lindl. has been isolated a new furocoumarin (I), C10H14O5, with mp 136.5–138.5°C (from ethanol), [α]D20 ± 0° (chloroform), which we have calledgosferol.On the basis of a study of the UV, IR, NMR, and mass spectra and the chemical properties of gosferol, the structure 5-(2″-hydroxy-3″-methylbutenyloxy)furo-2′,3′:7,6-coumarin has been proposed for it.

Application of mass spectrometry in structural and stereochemical investigations

The mechanism of the process M+→(M-CO)+ during fragmentation, under the influence of electron impact, of some bicyclic amines with a nodal nitrogen atom and containing an oxo group in various positions of the bridged system is discussed. Data on the ionization potentials and low-voltage mass spectra and from high-resolution mass spectrometry are used.

Mass spectra of substituted 4-aminopiperidines with a shielded nitrogen atom

The principal fragmentation pathway of 4-aminopiperidines under the influence of electron impact are determined by charge localization on the nitrogen atom of the piperidine ring or on the nitrogen atom of the substituent in the 4 position. In the case of electron-donor substituents in the 4 position and in the absence of a substituent attached to the nitrogen atom of the polysubstituted piperidine ring the charge is primarily localized on the nitrogen atom of the substituent; this is expressed in the specific fragmentation pathways. The principles found in this research make it possible to establish the structures of nitrogen-containing compounds that are similar to the investigated compounds.

Mass-spectrometric study of 3,9-diazabicyclo- and 3,9-oxaazabicylo[3.3.1]nonanes

The mass spectra of substituted 3,9-diazabicyclo- and 3,9-oxaazabicyclo[3.3.1]-nonanes were studied as a function of competitive distribution of the charge between the N3 and N9 and O3 and N9 atoms and the properties of the substituents attached to the heteroatoms. It is shown that a characteristic peculiarity of the fragmentation of 3,9-diazabicyclo[3.3.1]nonanes is fragmentation of the molecular ion with an open structure that is formed by cleavage of the C1-C2 bond. The formation of an amine fragment with retention of the bicyclic structure with an exocyclic double bond attached to the quaternary N9 atom is characteristic for 3,9-oxaazabicyclo[3.3.1]nonanes. It is shown that this sort of behavior of the investigated compounds is determined by their structures and the properties of the heteroatoms in the saturated bicyclic systems.

Mass spectra and peculiarities of the fragmentation of some substituted piperidines

N-Substituted piperidines with R = CH2OCH3, (CH2)4COCH2, CH3COOC2H5, (CH2)2N(CH3)2, (CH2)2N(C2H5)2, N=0, CH3, H, COOC2H5, and OH were investigated by mass spectrometry. The ratios of the intensities of the peaks and the behavior of the amine fragments with exocyclic double bonds attached to the quaternary nitrogen atom that are formed from the molecular ion by detachment of a radical from the C2 atom and from the substituent attached to the nitrogen atom were studied. It is shown that the ratios of the intensities of the peaks of the amine fragments are determined both by the type of substituent and the energy of the ionizing electrons.

Mass spectra and three-dimensional structure of 4-hydroxypiperidine derivatives

The mass spectra of stereoisomeric derivatives of 4-hydroxypiperidines obtained at various ionizing-electron energies with the application of isotopic substitution and high-resolution mass spectrometry are examined. The character of the fragmentation of the piperidine ring as a function of the position and spatial orientation of the substituent is discussed.

Furocoumarins of the roots of Prangos ferulacea

SummaryIt has been established that the treatment of oxypeucedanin and oxypeucedanin hydrate with 20% sulfuric acid in ethanol forms, in addition to known substances, a new coumarin derivative (VI), C18H20O6, with mp 93–94.5°C, for which the structure of 5-(3″-ethoxy-2″-hydroxy-3″methylbutoxy)furo-2′,3′:7,6-coumarin has been proposed. On the basis of the investigation performed and the similarity of the structures of the compounds isolated, a hypothetical scheme of the biogenesis of furocoumarins inPrangos ferulacea (L.) Lindl. has been put forward.