The structure of vincarinine

Summary 1. A new base — vincarinine — has been isolated from the epigeal part ofVinca erecta Rgl. et Schmalh.2. On the basis of spectral characteristics and a comparison of some chemical reactions of vincaricine and vincarinine, the structure of vincaricin-16-al has been established for the latter.Institute of the Chemistry of Plant Substances, Academy of Sciences of the Uzbek SSR. Translated from Khimiya Prirodnykh Soedinenii, No. 2, pp. 164–166, March, 1971.     

Terpenoids of the oleoresin of Pinus pumila

Summary 1. The composition of the acid fraction of the oleresin ofPinus pumila (Pall.) Regel. has been studied, and from it has been isolated, in addition to known compounds, the methyl ester of a new labdane acetoxy acid.2. In the hydrocarbon fraction of the oleoresin 11 monoterpenes and 26 sesquiterpenes have been found (and 17 of the latter have been identified).3. The composition of the fraction of neutral oxygen-containing diterpenoids fromP. pumila differs considerably in its diterpenoid components from the corresponding fractions of the oleoresins of botanically related species-P. sibirica andP. koraiensis. Novosibirsk Institute of Organic Chemistry, Siberian Branch of the Academy of Sciences of the USSR. Translated from Khimiya Prirodnykh Soedinenii, No. 3, pp. 299–302, May–June, 1976.     

Isolation from atelia herbert-smithii pittier (sophoreae,leguminosae) and x-ray structure of cis-1-amino-3-hydroxymethyl-cyclobutane-1-carboxylic acid,an achiral non-protein amino acid

barcis-1-Amino-3-hydroxymethyl-cyclobutane-1-carboxylic Acid (1) has been isolated from Atelia herbert-smithii Pittier (Leguminosae) and its structure determined by spectroscopic and X-ray crystallographic methods. By a study of the 1H NMR spectrum of the crude extract, the relative amount of (I) to that of methanoproline in the plant was shown to be 1 to 1.15.     

Leuconine — A new alkaloid from Aconitum leucostomum and A. septentrionale

A new alkaloid — leuconine — has been isolated from the epigeal parts ofAconitum leucostomum andA. septentrionale, and its structure has been established on the basis of spectral characteristics. Institute of Chemistry of Plant Substances, Uzbekistan Academy of Sciences, Tashkent. Translated from Khimiya Prirodnykh Soedinenii, No. 5, pp. 538–540, September–October, 1992.     

Duryne,a new cytotoxic agent from the marine sponge Cribrochalinadura

Duryne, 1, a cytotoxic metabolite which inhibits the growth of both mouse and human tumor cell lines invitro has been isolated from the marine sponge Cribrochalinadura. Its structure has been assigned by spectral methods.     

Synthesis of Bioactive Pyrethroid, 3-Phenoxybenzyl 1R-trans-2, 2-Dimethyl-3-(2-chloro-1-propenyl) Cyclopropanecarboxylate

The title compound 1 has been prepared from (+)-3-carene (2) and found to have the same order of activity as its IR-cis isomer 3 reported by us earlier¹ The key intermediate methyl IR-trans-2, 2-dimethyl-3-(2-oxopropyl)cyclopropanecarboxylate (4) has been characterised.     

Gibberellins and substances related to them

Conclusions 1. The neutral metabolites elaborated byFusarium moniliforme (strain F-6) in various medi have been chromatographed and six known diterpenoids biogenetically related to the gibberellins have been identified.2. The influence of the rate of consumption of the source of C during fermentation and its chemical nature on the course of the biosynthesis of the gibberellins have been noted.3. Considerations have been put forward concerning the mechanism of the stimulation of the biosynthesis of the gibberellins in media containing fats which are based on modern ideas concerning the metabolism of diterpenes in a culture ofF. moniliforme.Khimiya Prirodnykh Soedinenii, Vol. 5, No. 3, pp. 156–163, 1969     

Compounds of the pyran series as components of the essential oils ofTanacetum boreale andAjania fastigiata

It has been established that the essential oils ofTanacetum boreale andAjania fastigiata contain as their main components 3-hydroxy-2,2,6-trimethyl-6-vinyltetrahydropyran and its acylated and oxidized derivatives.Institute of Chemical Sciences, Academy of Sciences of the Kazakh SSR, Alma-Ata. Translated from Khimiya Prirodnykh Soedinenii, No. 3, pp. 332–335, May–June, 1985.     

N-oxides of homoaporphine alkaloids from Merendera raddeana

The alkaloid complex of the leaves, stems, seeds, and seed pods ofMerendera raddeana Rgl. (familyLiliaceae) has been investigated. A number of known tropolone alkaloids and their photochemical isomers have been isolated together with the homoaporphine bases merenderine, kreysiginine, and O-methyl-kreysiginine and their N-oxides, which have not been described in the literature. One of them (merenderine N-oxide) has been characterized by its physical constants and has been investigated by IR, PMR, and mass-spectral methods. By a study of the PMR spectrum of the fraction of neutral alkaloids from the leaves of the plant it has been established that it consists mainly of a mixture of equal amounts of colchicine and cornigerine.V. I. Lenin Tashkent State University. Translated from Khimiya Prirodnykh Soedinenii, No. 1, pp. 86–91, January–February, 1991.     

Determination of the Absolute Configuration of the (−)-Me(EtO)(HO)P-Mo(CO)5 Coordination Complex by Decomplexation of the Organophosphorus Ligand

Abstract

The resolution of a chiral coordination complex (1) was recently carried out in our laboratory, and some stereochemical transformations of the resolved specie have been reported (L. P. Reiff, L. J. Szafraniec, D. I. Rossman and H. S. Aaron, Inorg. Chem. 1986, 25, 0000). Decomplexation studies of its organophosphorus ligand have now been carried out. Thus, treatment of the (?)-1 complex with two molar equivalents of triphenylphosphine yields (+)-ethyl methylphosphinate (2), considerably racemized, however, due to the 120°C temperature required to achieve decomplexation. To determine its optical purity and its absolute configuration, the latter was converted into the known S-(?)-3 thioic acid and S-(?)-4 methyl ester, respectively. While the method does not appear to be of synthetic utility for the preparation of optically active (decomplexed) organophosphorus species, the absolute configuration of the S-(?)-1 coordination complex is established on the basis of these stereochemical relationships.     

Glycosides of Erysimum

Summary The cardenolides of six species ofErysimum and ofSyrenia siliculosa have been studied. The cardiac glycosides erysimin and erysimoside have been found inE. altaicum, E. marschallianum, E. nuratensae, andS. siliculosa. In addition to these glycosides,E. diffusum has yielded desglucocheirotoxin, canescein, and a new cardenolide, erydiffuside,E. violascens has yielded gypsobioside, andE. cuspidatum has yielded a new glycoside cuspidoside.Khimiya Prirodnykh Soedinenii, Vol. 3, No. 2, pp. 173–178, 1967     

Influence of Composite Electrolyte Membrane for Proton Exchange Membrane Fuel Cells

The operation of proton exchange membrane fuel cell (PEMFC) under humidified condition using composite sulfonated polyether-ether ketones (sPEEK) membrane 1 is reported. Composite sPEEK membrane that were used in this report, have been produced and compared by additional of i.e. organic polymer (Acrylonitrile Butadiene Styrene) 2 and silica powder inorganic 3 to sPEEK polymer 1. Whereas, sPEEK 1, which is known as hydrocarbon polyelectrolyte membrane for PEMFC and direct methanol fuel cell (DMFC) to replace Nafion, has been the most used in both PEMFC and DMFC due to its good performance even though in low humidified condition it showed poor current density. Here we reported the effect of inorganic silica in hydrocarbon sPEEK membrane that contributes for a better water management system inside the cell, and showed 0.16 W/cm² of power density which is 78% higher than that of non-silica modified.     

Investigation of the chemical composition ofSaussurea frolovii, Ldb.

Summary A new triterpene alcohol saussurol and its O-acetate have been isolated fromSaussurea frolovii Lbd.Khimiya Prirodnykh Soedinenii, Vol. 1, No. 4, pp. 256–262, 1965     

The effect of sulfur and selenium substitutents on the regiochemistry of diels-alder reactions

2-Phenylthio-1,3-butadiene (1) and 2-phenylseleno-1,3-butadiene (2) have been generated in situ from their SO₂ adducts and reacted with a series of unsymmetrical dienophiles. The regiochemical results have been analyzed in terms of qualitative perturbation theory.     

Synthesis of natural triisopentenylated flavanone, euchrenone a2

Euchrenone a₂ (7) isolated from the roots ofEuchresta japonica has been synthesised from 3-prenylphloroacetophenone (1) by other workers. We carried out its cyclodehydrogenation with dichloro dicyano quinone (DDQ) to obtain 6-acetyl-5,7-dihydroxy-2,2-dimethylchromene (2) which was ethoxymethylated in the 7-position to give 6-acetyl-7-ethoxymethoxy-5-hydroxychromene (3). Chalcone condensation of3 and 4-ethoxymethoxy-3-C-prenylbenzaldehyde (4) gave 4,6′-bisethoxymethoxy-2′-hydroxy-6″, 6″-dimethyl-3-C-prenylpyrano (2″, 3″–4,3) chalcone (5) which cyclised with methanolic sodium acetate to give protected 5,4′-bisethoxymethoxy-6″, 6″-dimethyl-3′-C-prenylpyrano (2″, 3″–7,8) flavanone (6). Deprotection of6 with 4% methanolic HCl yielded (7) with melting point and spectral data identical to that of the natural compound.     

Synthesis and Stereochemistry of Some new Derivatives of 1,2-O-Cyclohexylidene-α-D-Xylofuranuronic Acid

Abstract

1,2-O-Cyclohexylidene-α-d-xylofuranuronic acid (2) has been converted into its 3-O-acetyl derivative and consecutively to the corresponding acid chloride and ethyl ester. Direct reaction of 2 with ethanol in the presence of p-to-luene sulphonic acid gave the ethyl ester. Reaction of 2 with phosphorus pentachloride in dry ether gave the acid chloride of 1,2-O-cyclohexylidene-3-O-dichlorophosphoryl–α-d-xylofuranuronic acid. Conformational data have been obtained from ¹H and ¹³C NMR measurements.     

A novel short and efficient asymmetric synthesis of statine analogues

The statine analogues 1a–c have been obtained in high optical purity via addition of the chiral acetate enolate 4 to the α-aminoaldehydes 5a–c, followed by transesterification.     

Saturated heterocycles 115: Cycloaddition of nitrilimine and nitrile oxide to norbornane- and norbornene-fused dihydro-1,3-oxazines

By cycloaddition of nitrilimine and nitrile oxide to diexo and diendo norbornane- and norbornene-fused structural isomeric dihydro-1,3-oxazlnes (1-3), tetracyclic 1,3-oxazino-1, 2,4-trlazolines (7-9) and 1,2,4-oxadiazolines (10-12) were obtained. With norbornehe dipolarophiles, which contain a C=N and a C=C bond, the cycloaddition takes place at the olefinic bond and the diexo compound 4 yields 13 regioselectively, whereas the diendo isomer 5 gives an Isomeric mixture of isoxazolines 14 and 15. From the diexo derivative 6, however, a bis-adduct 16 is formed. The stereostructures of the adducts have been elucidated by NMR spectroscopy.     

Synthesis of Curcumone and ar-Turmerone via β-Oxoalkylation Process

Abstract

In 1974 I outlined a synthesis of ar-turmerone (1)¹ by controlled chain extension from the acetyl terminus of mesityl oxide, using the Diels-Alder cycloaddition and its retro version to protect and reclaim, respectively, the unsaturated moiety. Recently, a simpler approach to ar-turmerone and curcumone (2) has been brought to completion and is described in the following.