Investigations in the field of tetracyclines

Summary The synthesis of 4-N-desdimethyl- (IIa) and 4-N-desmethyl-12a-deoxy-5a,6-anhydrotetracycline (IIb) has been effected.For preliminary communications, see [1].M. M. Shemyakin Institute of the Chemistry of Natural Compounds of the Academy of Sciences of the USSR. Translated from Khimiya Prirodnykh Soedinenii, No. 3, pp. 357–363, May–June, 1971. Original article submitted Feburary 26, 1971.     

Investigations in the filed of tetracyclines

Conclusions Some properties and transformations of the tetracycloxides and N-desmethyltetracyclines have been studied.[/p]For part LII, see [1].     

Investigations in the imidazole field

It has been established that various inorganic and organic bases can be used for the cyclization of 1,2-dialkyl-3-(-oxoalkyl[aralkyl])benzimidazolium halides into derivatives of pyrrolo[1,2-a]benzimidazole. The action of strong bases on quaternary benzimidazolium salts gives O-betaines—intermediates in the closure of the pyrrole ring.For part XL, see [1].     

Investigations in the field of lipids

Summary A number of derivatives of androstano [3, 2-b] pyrylium and androst-13-eno-[3, 2-b] pyrylium derivatives forming a new class of heterocyclic steroids has been obtained.Khimiya Prirodnykh Soedinenii, Vol. 1, No. 5, pp. 318–321, 1965     

Investigations in the field of lipids

Summary 1. The synthesis of the following neutral plasmalogens has been effected: -O-(octadec-1-enyl)-, distearoylglycerol, -O-(octadec-1-enyl)-, -dipalmitoylglycerol, -O-(hexadec-1-enyl)-, -distearoylglycerol, and -O-(pentadec-1-enyl)-, -dipalmitoylglycerol.2. During the synthesis, the following compounds were isolated and characterized by their physicochemical constants: the -octadec-1-enyl ether of glycerol, -(2-hydroxyoctadecyl) , -isopropylideneglyceryl ether, the tosylate of -(2-hydroxyoctadecyl) , -isopropylideneglyceryl ether, and -O-(2-tosyloxyoctadecyl) glycerol.3. The IR spectra of the -octadec-1-enyl ether of glycerol and the neutral plasmalogens have been studied.Khimiya Prirodnykh Soedinenii, Vol. 2, No. 6, pp. 367–371, 1966     

Investigations in the field of anthrapyridone

6-Bromo-N-methylpyridone reacts with phosphorus pentachloride at 180° C to form, 2, 6-dichloroanthrapyridine. The latter reacts with amines at moderate temperatures forming 6-amino-2-chloro derivatives of anthrapyridine and at high temperatures forming 2, 6-diamino-substituted anthrapyridines.For part III, see [1].     

Investigations in the field of polymerocyanines

A series of N-acyl-1, 2, 3, 4-tetrahydro-4-alkyl(aryl)iminobenzo[g]quinolines has been obtained by the condensation of N-acyl-1, 2, 3, 4-tetrahydro-4-oxobenzo[g]quinolines with primary amines.For part IV, see [1].     

Investigations in the field of polymerocyanines

Dimerocyanines containing rhodanine residues with an alkyl or a substituted alkyl group on the nitrogen atom have been synthesized. The influence of these substituents on the color and photo properties of these dimerocyanines and their solubility in ethanol has been studied.For part I, see [2].     

Investigations in the field of lipids

Summary A method for the separate quantitative determination of the furocoumarins ofFicus carica has been developed.Khimiya Prirodnykh Soedinenii, Vol. 3, No. 5, pp. 295–298, 1967     

Investigations in the field of oxygen-containing heterocycles

2-(4-Chloro-2-methyl-2-butenyl)tetrahydropyran and 2-(4-chloro2, 3-dimethyl-2-butenyl)tetrahydropyran react with organomagnesium compounds and also with sodium amalgam with the formation of mixtures of the 2-(2-alkenyl)tetrahydropyrans corresponding to the initial chlorides and the 2-(3-alkenyl)tetrahydropyrans corresponding to the allyl isomers of the initial chlorides. The structure and composition of the products have been established by IR and NMR spectroscopy and by gas-liquid chromatography.For part V, see [1].     

Investigations in the field of benzimidazole derivatives

The influence of the electron-donating groups CH₃O, N(CH₃)₂, OH, NH₂, CH₃ in various positions of the benzimidazole molecule on the occurrence of the Chichibabin reaction in this series has been studied. While all monosubstituted 1-alkylbenzimidazoles undergo amination with sodium amide with greater or smaller readiness, 5,5-dimethoxy-and 5,6-methylenedioxybenzimidazoles do not take part in this reaction. The behavior of benzimidazole derivatives toward sodium amide is discussed from the point of view of the electron density at the pyridine nitrogen atom and at the C₂ atom of the imidazole ring, which was evaluated on the basis of molecular orbital calculations, ionization constants, and the chemical shifts of the protons attached to the C₂ atom in the PMR spectra.For Communication XXI, see [1].Translated from Khimiya Geterotsiklicheskikh Soedinenii, Vol. 6, No. 8, pp. 1060–1065, August, 1970.     

Investigations in the field of complex lipids

Summary 1. The synthesis of L-(+)--oleoyl--linoleoyl--glycerylphosphorylethanolamine has been effected.2. During the investigations the following substances were isolated and characterized: L--oleoyl--glycerylphosphoryl-N-phthaloylethanolamine and L---linoleoyl--glycerylphosphoryl-N-phthanoylethanolamine.Khimiya Prirodnykh Soedinenii, Vol. 2, No. 2, pp. 80–83, 1966     

Investigations in the field of higher fullerenes

Halogenation of higher fullerene mixtures or their perfluoroalkylation with R^FI followed by HPLC separation of R^F derivatives and subsequent synchrotron X-ray crystallographic study made it possible to confirm cage connectivities of higher fullerenes and, in addition, to receive information concerning their reactivity in radical addition reactions. The data obtained are compared with theoretical predictions for higher fullerenes. Addition patterns of higher fullerene derivatives are discussed. Skeletal rearrangement of the D ₂-C₇₆ cage during chlorination has been observed for the first time.     

Investigations in the field of oxygen-containing heterocycles

In the presence of stannic chloride, 2,3-dichlorotetrahydrofuran adds to isoprene with the formation of 3-chloro-2-(4-chloro-2-methylbut-2-enyl)tetrahydrofuran and to piperylene and bivinyl with the formation, predominantly, of 3-chloro-2-(4-chloropent-2-enyl)- and 3-chloro-2-(4-chlorobut-2-enyl)tetrahydrofuran, respectively, with their allyl isomers. The amount of the latter was estimated from the NMR spectra at 20–30%.For part VII, see [1].     

Investigations in the field of pyrazolidine chemistry

On hydrogenation in neutral ethanolic solution in the presence of a Raney nickel catalyst, 1, 2, 4-trisubstituted 3, 5-dioxopyrazolidines undergo hydrogenolysis at the N-N bond. The enolate anions of these compounds and the fixed enolic form are stable to hydrogenolysis.For part XIII, see ¦1¦.