I. Yu. Bagryanskaya

Synthetic transformations of methylenelactones of eudesmanic type. Behavior of isoalantolactone under the conitions of heck reaction

By Heck reaction of isoalantolactone with aryl bromides or aryl iodides (3aR,4aS, 8aR,9aR,E)-3-arylmethylidene-8a-methyl-5-methylidenedecahydronaphtho[2,3-b]furan-2(3H)-ones and (4aS,8aR,9aS)-3-arylmethyl-8a-methyl-5-methylidene-4a,5,6,7,8,8a,9,9a-octahydronaphtho[2,3-b]furan-2(4H)-ones, products of the double bond shift, were synthesized. The yields of the arylation products depend on the nature of the catalytic system and on the structure of the aryl halide. The structures of (3aR,4aS,8aR,9aR,E)-3-(3,4-dimethoxybenzylidene)-8amethyl-5-methylidenedecahydronaphtho[2,3-b]furan-2(3H)-one and (4aS,8aR,9aS)-3-(2-methylsulfanylbenzyl)-8amethyl-5-methylidene-4a,5,6,7,8,8a,9,9a-octahydronaphtho[2,3-b]furan-2(4H)-one were proved by XRD analysis.

Sesquiterpene lactones and flavonoids from Artemisia albida

The five known lactones matricarin, austricin, canin, and achillin guaianolides and argolide germacranolide and the two flavonoids eupatilin and its 7-O-methyl ester were isolated for the first time from the aerial part of Artemisia albida Willd. The structure of eupatilin was confirmed by an x-ray structure analysis.

3-Oxocostusic acid fromArtemisia altaiensis

From the epigeal part ofArtemisia altaiensis Krash. we have isolated 3-oxocostus acid (selina-4,11(13)-dien-3-on-12-oic acid), the structure of the molecule of which has been confirmed by x-ray structural analysis, while its absolute configuration has been established from the results of circular dichroism.

MOLECULAR STRUCTURE OF AZACHALCOGENENES WITH AROMATIC SUBSTITUENTS

The molecular structure of acyclic and cyclic azachalcogenenes with aromatic substituents is analyzed and compared with related compounds using the data of XRD, NMR, and quantum chemical calculations.

Synthetic transformations of higher terpenoids. XXI.* Preparation of phlomisoic acid and its N-containing derivatives

A method for preparing 15,16-epoxylabda-8(9),13(16),14-trien-18-oic (phlomisoic) acid was proposed. Its structure was confirmed by an XSA. N-containing derivatives of phlomisoic acid that contained amines, hydrazides, and methyl esters of amino acids on the C-18 atom in addition to (2-oxo-2-aminoacetyl)-substituted derivatives of the C-16 methyl ester of phlomisoic acid were prepared.

Preparation and structure elucidation of two minor products from reaction of arglabin with chloroform in the presence of a crown ether

A pentachloro derivative, the structure of which was proved by x-ray structure analysis, in addition to a new dichlorocarbene derivative were obtained for the first time by dichlorocyclopropanation of arglabin guaianolide. The stereochemistry of the principal reaction product was established.

First synthesis of dialkyl phosphonate derivatives of sesquiterpene α-methylene-γ-lactone

The stereoselective synthesis of two phosphorus-containing derivatives of the known guaianolide arglabin was carried out for the first time. The molecular structures of these products were established based on the spectroscopic data and the results of X-ray diffraction analysis of one of these compounds.

Plant coumarins: VI. Synthesis of 3-vinylfurocoumarin derivatives based on oreoselone

Palladium-catalyzed Heck reaction of oreoselone trifluoromethanesulfonate with various terminal alkenes (methyl acrylate, styrene, vinylpyridines, N-vinylpyrrole, and N-vinyl-1,2,4-triazole) led to the formation of the corresponding (E)-3-vinyl-7H-furo[3,2-g]chromen-7-ones. The yield was found to depend on the catalytic system and initial olefin structure.

Photocyclization of 2-azido-1-(4-tert-butylphenoxy)-9,10-anthraquinone in the presence of substituted phenols

New types of phototransformations in the quinone series, viz., photocyclizations of 1-aryloxy-2-azido-9,10-anthraquinone in the presence of phenols, were studied. The photolysis affords mainly 5H-naphtho[2,3-c]phenoxazine-8,13-diones, in which the nitrogen atom is covalently bound to the phenyl ring of the attached phenol. As a result, complex polycyclic derivatives of phenoxazines were prepared in high yields in one step.

Reactions of chloro-substituted enaminoketones,viz., derivatives of imidazolidine nitroxides, with sodium cyanide

The reactions of chloro-substituted enaminoketones,viz., derivatives of imidazolidine nitroxides, with sodium cyanide afford the corresponding nitriles. The reactions proceed through formation of epoxides. The structure of one of these epoxides was confirmed by X-ray diffraction analysis.