L-Vinylglycine from L-Homoserine.

A simple and practical synthesis of L-vinylglycine starting from L-homoserine is described.     

Polyimides derived from bismethylolimides. II. Polyamine-imides from bismethylolimides and diamines

Compounds in the N-methylolimide group reacted smoothly with amines in the presence of water to yield the corresponding condensation products. Polycondensations of bismethylolimides, N,N′-bismethylolpyromellitic diimide, and N,N′-bismethylolbenzophenonetetracarboxylic diimide, with amines such as aromatic diamines, piperazine, and n-butylamine, were carried out in DMAc that contained 1% water to produce linear polyamine-imides. The polyamine-imides assumed various colors, from very pale yellow to deep purple, and had inherent viscosities in the 0.07–0.37-dl/g range. Most of these polymers were soluble in polar solvents such as DMAc and DMSO. The thermal stability of the polymers was examined by thermogravimetric analysis; decomposition started at 210–350°C and weight residue at 500°C was 22–85% in air.     

Polysaccharides of Polygonatum. VII. A glucofructan from P. sewerzowii

A glucofructan has been isolated from the rhizomes ofPolygonatum sewerzowii Bunge and has been called pseverin. According to its chemical and spectral characteristics, pseverin is a polysaccharide containing both inulin, 2 1, and leven, 2 6, glycosidic bonds. The problem of the correlation between the molecular structure of a glucofructan and its supermolecular organization has been considered. X-radiographic and electron-microscope studies have been made of pseverin and its acetate. It has been established that on precipitating from solution pseverin forms globular particles which aggregate to give elongated necklace-like formations. Fine lamellar structures are characteristic for the acetate.Institute of the Chemistry of Plant Substances, Academy of Sciences of the Uzbek SSR, Tashkent. Translated from Khimiya Prirodnykh Soedinenii, No. 1, pp. 15–20, January–February, 1986.     

Steroid compounds from ophiuroids. I. New steroid sulfate from Ophiura sarsi

The sulfate of a steroid polyol has been isolated from the Far Eastern ophiuroidOphiura sarsi, and its structure has been established by chemical and spectral methods as cholest-5-ene-3,4,21-diol 3-(sodium sulfate). No steroid compounds of such structure from ophiuroids have been described previously.Pacific Ocean Institute of Bioorganic Chemistry, Far Eastern Branch, USSR Academy of Sciences, Vladivostok. Translated from Khimiya Prirodnykh Soedinenii, No. 3, pp. 375–379, May–June, 1988.     

Alternating Copolymers from Alkyleneimines. I. Copolymers from Ethyleneimine and Dicarboxylic Anhydrides

Ethyleneimine and dicarboxylic anhydrides were copolymerized to alternating copolymers which possess an ester-amide in the repeating unit. The structure of copolymer was Identified by IR, NMR, and elemental analysis. On taking the structure of copolymer, the nucleophllic reactivity of ethyleneimine, and the electrophilic nature of dicarboxylic anhydride Into consideration, a reaction mechanism was elucidated. It Involves ring opening and a stepwise addition reaction in alternating manner, in that one monomer undergoes ring opening and chain propagation exclusively through the interaction with another monomer that is already present at the polymer chain end. The copolymers obtained from halogen containing dicarboxylic anhydrides are useful as fire-retarding additives for plastics and also as thermosetting resin precursor when anhydrides are partially replaced by maleic anhydride.     

Triterpenoids from Abies sp. IX. Triterpene lactones from Abies sibirica bark

Four lanostane lactones have been isolated from an ethereal extract of Siberian fir bark — abieslactone and its hydroxy and keto analogs, and also (25R)-24,25-dihydroabieslactone, the structure of which was established on the basis of a chemical and spectral correlation with known compounds.Novosibirsk Institute of Organic Chemistry, Siberian Branch, USSR Academy of Sciences. Translated from Khimiya Prirodnykh Soedinenii, No. 2, pp. 220–225, March–April, 1989.     

Triterpenoids from Abies species. IV. New triterpene acids from the needles of Abies sibirica

Four new triterpene acids of the mariesiic acid series have been isolated from an extract of the needles of the Siberian fir in the form of their methyl esters, and their structures have been established on the basis of chemical transformations, spectral characteristics, and x-ray structural analysis.Novosibirsk Institute of Organic Chemistry, Siberian Branch, USSR Academy of Sciences. Translated from Khimiya Prirodnykh Soedinenii, No. 6, pp. 824–831, November–December, 1987.     

Novel orthohalogenation reaction. Synthesis of orthochloroarylamines from nitroarenes.

Thionyl chloride reacts with N-phenylbenzo and N-phenylacetohydroxamic acids at low temperatures to give ortho-chloroanilide derivatives in good yield.     

Triterpenoids from Abies species. IV. New triterpene acids from the needles of Abies sibirica

Four new triterpene acids of the mariesiic acid series have been isolated from an extract of the needles of the Siberian fir in the form of their methyl esters, and their structures have been established on the basis of chemical transformations, spectral characteristics, and x-ray structural analysis.     

Cyclization of ylidenemalononitriles. VIII. Synthesis of coumarins from o-methoxybenzylidenemalonitriles

A new synthesis of coumarins, by direct cyclization of α-cyano-o-methoxycinnamates in sulfuric acid, is described. The reaction seems quite general, and alkoxy groups other than the o-methoxy group involved in lactone formation are not hydrolyzed during the reaction. The 3-cyano group on the resulting coumarin is not hydrated in concentrated sulfuric acid, but can be converted to the carbamido group in 90% sulfuric acid. In certain cases these conditions do cleave methoxy substituents on the coumarins. Although the sulfuric acid cyclization did not produce the usual indenones when an o-methoxy group was present, the corresponding indenones could be obtained by cyclizing the ylidenemalononitriles with boron trifluoride-etherate. Possible reasons for this selectivity are discussed, and new coumarins and indenones characterized.     

Isoindoles from phthalimidines. N-arylisoindoles

A convenient method was developed for the preparation of N-arylisoindoles by the reduction of the corresponding phthalimidines.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 12, pp. 1629–1631, December, 1987.