Crystal structure of pseudokopsinine and its salts

The X-ray diffraction study of an indoline alkaloid, pseudokopsinine, extracted from the plant Vinca erecta and its mono- and double salts is performed. The experimentally determined positions of Н atoms suggest the sp ³ hybridization of the indoline nitrogen atom in the base and salts. The pseudokopsinine base and double salt have an intramolecular Н bond between the NH group proton and the ether oxygen atom of the methoxycarbonyl group, which is absent in the monosalt and the related indolines. The intermolecular Н bonds and/or the packing efficiency cause a conformational change in F and Е heterocycles in the indoline hetero framework of pseudokopsinine salts in comparison with that observed in the base.     

Dimeric indoline alkaloids of a new biphenyl type

A ¹³C NMR analysis of lochnericine and the new alkaloids peceyline, peceylanine and pelankine is presented and the structures of the indoline dimers described.     

The NMR investigation of alkaloids. VII.13C NMR spectra and structure of “kopsanone” and kopsinilam

On the basis of a study of the¹³C NMR spectra of a base fromVinca erecta previously regarded as kopsanone, and the known alkaloid kopsinilam, it has been shown that the former is 5,22-dioxokopsane.Institute of the Chemistry of Plant Substances, Academy of Sciences of the Uzbek SSR, Tashkent. Translated from Khimiya Prirodnykh Soedinenii, No. 3, pp. 344–346, May–June, 1984.     

Crystal structure of the sulfonium salts of natural azulenes

The molecular and crystal structure of dimethyl-(1,4-dimethyl-7-ethylazulyl)-sulfonium perchlorate and dimethyl-(1,4-dimethyl-7-isopropylazulyl)-sulfonium perchlorate was determined by X-ray diffraction analysis. Their crystal structure is mainly determined by C-H...π intermolecular interactions.     

Crystal structure of salts of indole alkaloid norfluorocurarine

Single crystal XRD is used to study the crystals of salts of indole alkaloid norfluorocurarine: hydrochloride recrystallized from absolute alcohol, dihydrate hydrochloride recrystallized from water, methochloride monohydrate recrystallized from water, solvate form of methochloride obtained from ethanol, and methobromide monohydrate. Intra- and intermolecular hydrogen bonds are analyzed in these crystals. The crystal structures of norfluorocurarine methochloride and methobromide monohydrates are isomorphic. In norfluorocurarine salts, the orientation of the carbonyl group is determined by the intramolecular C19=O…H-N1 hydrogen bond that is absent in the solvate form with ethanol.     

Approach to the synthesis of indoline derivatives from diaryliodonium salts

An effective method of constructing the indoline moiety via intramolecular nucleophilic ring closure of a diaryliodonium salt is described. Diacetoxyiodoarene compounds (1a-1e) were converted into intermediate Koser's reagent and coupled with arylstannanes (7-10) to form diaryliodonium salts (11a-14e). Indoline compounds with different N-protecting groups, 15, 16, 17, and 18, were synthesized in higher yields by treating salts (11a-14e) with Cs(2)CO(3) and TEMPO. Regardless of the electronic environment of five para-substituted iodoarenes and the natures of four N-protected arylstannane groups, the conversion proceeded well to afford corresponding indolines in yields of 72-84 and 70-84%, respectively.     

Optical rotatory dispersion of indoline alkaloids with keto groups

The optical rotatory dispersion curves of a series of indolines, N(a)-acetyl-indolines and N(a)-methoxycarbonyl-indolines containing keto groups have been measured. It has been shown that the absolute stereochemistry of N(a)-acetyl-indolines containing keto groups can still be determined from the character of the Cotton Effect due to the aromatic chromophore, the ketone Cotton Effect however being more difficult to interpret. The use of N(a)-methoxycarbonyl-indoline and indoline chromophores is dangerous due to the complex nature of the Cotton Effect of the former and the overlapping of that of the latter with the ketone Cotton Effect.     

Quaternary salts of alkaloids

New biologically active quaternary salts of the alkaloids ajmaline, quinine, hyoscyamine, codeine, and strychnine were synthesized. So-called separable conformers were observed among the ajmaline derivatives. __________ Translated from Khimiya Prirodnykh Soedinenii, No. 4, pp. 381–383, July–August, 2006.     

Difference in the signals of the N-H proton in the NMR spectra of the indole, indoline, and hydroxyindole alkaloids

Conclusions On the basis of the results of measurements of the chemical shifts of the signal of the NH proton in Vinca alkaloids, it has been established that the CS of the NH group in the -methyleneindoline alkaloids and their 2, 16-dihydro derivatives differ substantially.Khimiya Prirodnykh Soedinenii, Vol. 6, no. 1, pp. 89–90, 1970     

Difference in the signals of the N-H proton in the NMR spectra of the indole,indoline, and hydroxyindole alkaloids

Chemistry of Natural Compounds - On the basis of the results of measurements of the chemical shifts of the signal of the NH proton in Vinca alkaloids, it has been established that the CS of the NH...     

Synthesis and structure of indoline spiropyrans of the coumarin series

New indoline spiropyrans of the coumarin series were synthesized by the condensation of indoline and hydroxyformylcoumarin derivatives. Spiropyrans, viz., derivatives of 8-formyl-7-hydroxy-4-methylcoumarin and 5-formyl-6-hydroxy-4-methylcoumarin, under irradiation are transformed into open forms, which are recyclized in the dark. The compounds formed by the condensation of the indoline derivatives with 3-formyl-4-hydroxycoumarin have an open structure of the merocyanine dyes and are transformed into spiro forms neither in the dark nor under irradiation with the visible light. Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 10, pp. 2342–2349, October, 2005.     

Crystal structure of new carboxylate phosphabetaines and phosphonium salts conjugated with them

Russian Chemical Bulletin - Earlier unknown crystalline forms of three carboxylate phosphabetaines and conjugated with them phosphonium salts differing by β substituent with respect to the...     

Crystal and molecular structure of N-(benzylimidazolyl-2)-O-methylcarbamate salts

Single crystal X-ray diffraction has been applied to determine the structure of salts — formate and hydrochloride of N-(benzylimidazolyl-2)-O-methylcarbamate (BMC). The crystal structure of BMC formate is built by a molecule of a base and two formic acid molecules, one of them protonating a BMC molecule. Hydrogen bonds in the crystal form a weakly bound one-dimensional ribbon. BMC hydrochloride crystallizes as dihydrate. Two molecules of crystallization water and Cl ion make a robust H-bonded two-dimensional layer. BMC salts are formed through the protonation of N9 atom.     

X-ray structural investigation of alkaloids VI. Crystal structure of the alkaloid parfumine

A complete x-ray structural investigation of the alkaloid parfumine has been performed. The lengths of the bonds and the valence angles have the usual values. Benzene rings A and D are planar, B a distorted half-chair^C(6)H_N, and rings C and E are flattened envelopes, E_C(14) and^C(19)E, respectively.Institute of the Chemistry of Plant Substances, Academy of Sciences of the Uzbek SSR, Tashkent. Institute of Heteroorganic Compounds, Academy of Sciences of the USSR, Moscow. Translated from Khimiya Prirodnykh Soedinenii, No. 1, pp. 66–73, January–February, 1980.     

X-ray structural investigation on alkaloids V. Crystal and molecular structure of sibiricine

Summary A complete x-ray structural investigation of the spirobenzy1isoquinoline alkaloid sibiricine in the form of the base has been carried out. The bond lengths and valence angles are the usual ones.Translated from Khimiya Prirodnykh Soedinenii, No. 6, pp. 752–758, November-December, 1978. Original article submitted July 4, 1978.     

Crystal structure and spectroscopic behavior of three new tris-oxalatoferrate(III) salts

A new general synthetic procedure for preparation of Na₃[Fe(C₂O₄)₃]·5H₂O (1), Rb₃[Fe(C₂O₄)₃]·3H₂O (2), and Cs₃[Fe(C₂O₄)₃]·2H₂O (3) was developed. The crystal structures of these salts have been determined by single crystal X-ray diffraction. Salt 1 crystallizes in the monoclinic space group C2/c with Z = 8, salt 2 in P2₁/c with Z = 4, and salt 3 in P2₁/n with Z = 4. The three new salts and K₃[Fe(C₂O₄)₃]·3H₂O, prepared for comparative purposes, were further characterized by infrared and ⁵⁷Fe-Mössbauer spectroscopy. These spectra are discussed in comparison with those of related oxalato complexes.