19-nor-11-Oxooleanan-12-ene and 18,19-seco-19-oxours-11,13(18)-diene triterpenes from Diospyros decandra bark

Four new triterpenes, 2α,3β-dihydroxy-19-nor-11-oxo-20-dimethylurs-12-en-24,28-dioic acid (equivalent to 2α,3β-dihydroxy-19-nor-11-oxoolean-12-en-24,28-dioic acid), 2α,3β-dihydroxy-18,19-seco-19-oxours-11,13(18)-dien-24,28-dioic acid, 2α,3β,19α-trihydroxy-11-oxours-12-en-24,28-dioic acid and 2α,3β,19α-trihydroxy-28-1′-β-d-[glucopyranosyl-(1″→6′)-glucopyranosyl]-urs-12-en-24,28-dioic acid were isolated from the methanol extract of the bark of Diospyros decandra as their acetate-methyl ester derivatives. The first two compounds represent the biosynthetic transformation products of 2α,3β,19-trihydroxyurs-24,28-dioic acid via oxidative rearrangement of ring E.     

Lupane-triterpene carboxylic acids from the leaves of Acanthopanax trifoliatus

Two new lupane-triterpene carboxylic acids, called acantrifoic acid A (1) and acantrifoside C (2) have been isolated from the leaves of Acanthopanax trifoliatus. Based on extensive 1D and 2D NMR spectroscopic data, their chemical structures were determined as 3 alpha-acetoxy-30-hydroxylup-20(29)-ene-23,28-dioic acid and 3 alpha-acetoxy-30-hydroxylup-20(29)-ene-23,28-dioic acid 28-O-alpha-L-rhamnopyranosyl-(1-->4)-beta-D-glucopyranosyl-(1-->6)-beta-D-glucopyranosyl ester.     

Synthesis and total 1H- and 13C-NMR assignment of cephem derivatives for use in ADEPT approaches

We report the synthesis and total NMR characterization of 5-thia-1-azabicyclo-[4.2.0]oct-2-ene-2-carboxylic acid-3-[[[(4'-nitrophenoxy)carbonyl]oxy]-methyl]-8-oxo-7-[(2-thienyloxoacetyl)amino]-diphenylmethyl ester-5-dioxide (5), a new cephalosporin derivative. This compound can be used as the carrier of a wide range of drugs containing an amino group. The preparation of the intermediate product, 5-thia-1-azabicyclo[4.2.0]oct-2-ene-2-carboxylic acid-3-[methyl 4-(6-methoxyquinolin-8-ylamino)pentylcarbamate]-8-oxo-7-[(2-thienyloxoacetyl)amino]-diphenylmethyl ester-5-dioxide (6), as well as the synthesis of the antimalarial primaquine prodrug 5-thia-1-azabicyclo[4.2.0]oct-2-ene-2-carboxylic acid-3-[methyl 4-(6-methoxyquinolin-8-ylamino)pentylcarbamate]-8-oxo-7-[(2-thienyloxoacetyl)amino]- 5-dioxide (7) are also described, together with their total (1)H- and (13)C-NMR assignments.     

Synthesis of fluorinated cyclic s-trans vinylogous acid and amide ester derivatives

A two-step procedure for the preparation of ethyl 4-amino-2-oxo-6-(trifluoromethyl)cyclohex-3-ene-1-carboxylate (enaminone) and methyl 4-hydroxy-2-oxo-6-(trifluoromethyl)cyclohex-3-ene-1-carboxylate (vinylogous acid) has been accomplished, using reactive Michael acceptors under basic condition. In addition, acyclic trifluoromethylated ester derivatives were isolated as competing by-products. The above compounds represent novel synthetically useful trifluoromethyl building blocks.     

Synthesis of ecdysone. 3. On insect hormones. Syntheses of 2-beta, 3-beta, 14-alpha-trihydroxy-6-keto-delta-7-A-B-cis-steroids

The synthesis of the tetracyclic skeleton of ecdysone with correct stereochemistry and substitution is described. 22,25-Didehydroxy-ecdysone and methyl (20S)-2β,3β-dihydroxy-6-oxo-5β-pregn-7-ene-20-carboxylate have been prepared. The latter is a key intermediate in the synthesis of ecdysone.     

Reactions of arylfurans with acetylenedicarboxylic acid

A mixture of substances consisting of anhydrides of substituted phthalic acids (products of the diene synthesis) and 2-(5-aryl-2-furyl) but-2-ene-1,4-dioic acids (products of substitutive addition) is formed in the reaction of arylfurans with acetylenedicarboxylic acid.Deceased.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 9, pp. 1170–1172, September, 1982.     

Synthesis and antimicrobial activity of some derivatives of (7-hydroxy-2-oxo-2H-chromen-4-yl)-acetic acid hydrazide

(7-Hydroxy-2-oxo-2H-chromen-4-yl)-acetic acid hydrazide (2) was prepared from (7-hydroxy-2-oxo-2H-chromen-4-yl)-acetic acid ethyl ester (1) and 100% hydrazine hydrate. Compound 2, is the key intermediate for the synthesis of several series of new compounds such as Schiff's bases 3a-l, formic acid N'-[2-(7-hydroxy-2-oxo-2H- chromen-4-yl)acetyl] hydrazide (4), acetic acid N'-[2-(7-hydroxy-2-oxo-2H-chromen-4- yl)-acetyl] hydrazide (5), (7-hydroxy-2-oxo-2H-chromen-4-yl)-acetic acid N'-[2-(4- hydroxy-2-oxo-2H-chromen-3-yl)-2-oxoethyl] hydrazide (6), 4-phenyl-1-(7-hydroxy-2- oxo-2H-chromen- 4-acetyl) thiosemicarbazide (7), ethyl 3-{2-[2-(7-hydroxy-2-oxo-2H- chromen-4-yl)-acetyl]hydrazono}butanoate (8), (7-hydroxy-2-oxo-2H-chromen-4-yl)- acetic acid N'-[(4-trifluoromethylphenylimino)methyl] hydrazide (9) and (7-hydroxy-2- oxo-2H-chromen-4-yl)acetic acid N'-[(2,3,4-trifluorophenylimino)-methyl] hydrazide (10). Cyclo- condensation of compound 2 with pentane-2,4-dione gave 4-[2-(3,5- dimethyl-1H-pyrazol-1-yl)-2-oxoethyl]-7-hydroxy-2H-chromen-2-one (11), while with carbon disulfide it afforded 7-hydroxy-4-[(5-mercapto-1,3,4-oxadiazol-2-yl)methyl]-2H- chromen-2-one (12) and with potassium isothiocyanate it gave 7-hydroxy-4-[(5- mercapto-4H-1,2,4-triazol-3-yl)methyl]-2H-chromen-2-one (14). Compound 7 was cyclized to afford 2-(7-hydroxy-2-oxo-2H-chromen-4-yl)-N -(4-oxo-2-phenylimino- thiazolidin-3-yl) acetamide (15).     

(Z)-7-Nitro-3-Heptene as Central Intermediate for the Synthesis of Jasmone,Methyl Jasmonate,and γ Jasmolactone

(Z)-7-Nitro-3-heptene is used as central intermediate in the synthesis of jasmone (13), methyl jasmonate (15), and γ-jasmolactone (16), three jasmin constituents.

Conjugate addition of the title nitro compound, by heterogeneous catalysis, to methyl vinyl ketone, or acrolein, or methyl acrylate, followed by Nef reaction, affords (Z)-undec-8-ene-2,5-dione, (Z)-1,4-dioxodec-7-ene, and (Z)-4-oxo-dec-7-enoic acid methyl ester respectively, which are easily converted into jasmone, methyl jasmonate and γ -jasmolactone.     

Synthetic transformations of higher terpenoids: XVII. Intramolecular cyclization of N-furfuryl amides of the labdane series

16-(Benzylaminomethyl)lambertianic acid methyl ester reacts with 2-methylprop-2-enoyl chloride to give unsaturated amide which readily undergoes intramolecular [4 + 2]-cycloaddition with formation of terpenoid derivatives of 10-oxa-3-azatricyclo[5.2.1.0^1,5]decenone. Acetylation of lambertianic acid methyl ester with acetic anhydride occurs preferentially at the 2-position of the furan ring and is accompanied by migration of the exocyclic double bond. Reductive amination of 16-acetyl-15,16-epoxylabda-8(9),13,14-triene and subsequent reaction of the resulting amine with 2-methylprop-2-enoyl chloride give intramolecular cyclization products in high yield without isolation of intermediate furfurylacryloyl derivative. Reactions of methyl 16-(benzylaminomethyl)-15,16-epoxylabda-8(9),13,14- and -8(17),13,14-trien-18-oates with maleic anhydride lead to the formation of the corresponding 10-oxa-3-azatricyclo[5.2.1.0^1,5]dec-8-ene-6-carboxylic acid derivatives as mixtures of diastereoisomers.     

Cytotoxic lupane-, secolupane-, and oleanane-type triterpenes from Viburnum awabuki

Bioassay-guided fractionation of the methanolic extract of Viburnum awabuki afforded two new lupane triterpene derivatives; 6 beta-hydroxyl-3,20-dioxo-30 norlupane-28-oic acid (1) and 3,4-secolup-4,20-dihydroxy-3,28-dioic acid-3-oic acid methyl ester (2), along with seven known lupane and oleanane-type triterpenes (3-9). The structure of the isolated compounds was assigned using different spectroscopic techniques including 1D and 2D NMR. The 13CNMR data of compounds 5 and 9 is reported for the first time. Triterpenes 1, 2, and 7-9 showed in vitro cytotoxic activity against several tumor cell lines.     

Carbon-13 NMR spectra of some pentacyclic triterpenoids with the olean-12-ene and 18α-olean-12-ene skeleton

The ¹³C NMR spectra of some pentacyclic triterpenoids, 3β-acetoxy-11-oxo-olean-12-ene-30-oic acid methyl ester, 3β-acetoxy-11-oxo-olean-12-ene-29-oic acid methyl ester, the corresponding 11-desoxo methyl esters, 3β-acetoxy-11-oxo-18α-olean-12-en-30-oic acid methyl ester and 3β-acetoxy-11-oxo-18α-olean-12-en-29-oic acid methyl ester are discussed. The shielding data are interpreted in term of the different orientation of the carbomethoxy group and of the change in configuration at the D/E ring junction and are diagnostically valuable for the differentiation of the mentioned compounds.     

Synthetic transformations of higher terpenoids: XXIII. Synthesis of diterpenoid-based dihydroisoindolones

Vilsmeier-Haak reaction of phlomisoic acid methyl ester gave a mixture of 15- and 16-formyllabdanoids. In addition, methyl 2-formyldodecahydrophenanthro[1,2-b]furan-6-carboxylate was isolated, and its structure was determined by X-ray analysis. Reductive amination of 16-formyllabdanoid with benzylamine or α-amino acid methyl esters led to the formation of labdanoid furfurylamines which reacted with maleic anhydride to produce N-substituted 4-oxo-10-oxa-3-azatricyclo[5.2.1.0^1,5]dec-8-ene-6-carboxylic acids. Acylation of labdanoid furfurylamines with (E)-but-2-enoyl chloride afforded the corresponding unsaturated amides which were converted into 10-oxa-3-azatricyclo[5.2.1.0^1,5]dec-8-en-4-ones via intramolecular Diels-Alder reaction. Treatment of the oxa adducts with boron trifluoride-diethyl ether complex gave dihydroisoindol-1-one derivatives containing a diterpene fragment.     

Complete assignments of 1H and 13C NMR spectral data for three new triterpenoid saponins from Ilex hainanensis Merr

Three new oleanane-type triterpenoid saponins, ilexhainanoside C, D and E, all with 24, 28-dioic acid groups, were isolated from the leaves of Ilex hainanensis. They were 3beta-hydroxyolean-12-ene-24, 28-dioic acid-28-O-beta-D-glucopyranoside(1), 3beta, 19alpha-dihydroxyolean-12-ene-24, 28-dioic acid-28-O-beta-D-glucopyranoside(2) and 3beta, 29-dihydroxyolean-12-ene-24, 28-dioic acid-28-O-beta-D-glucopyranoside(3). The structures of these three new compounds were elucidated and complete assignments of the (1)H and (13)C NMR spectroscopic data were achieved by 1D and 2D NMR experiments [heteronuclear single quantum coherence (HSQC), HMBC and rotational nuclear Overhauser effect spectroscopy (ROESY)].     

Sulfated lupane triterpene derivatives and a flavone C-glycoside from Gypsophila repens

A new sulfated lupane triterpene, Gypsophilin (1), and its glucosyl ester, Gypsophilinoside (2) were isolated from the roots of Gypsophila repens whereas a new flavone C-glycoside (3) was obtained from the aerial parts. Their structures were established as (3beta)-3-O-(sulfo)lup-20(29)-en-23,28-dioic acid (1), (3beta)-3-O-(sulfo)lup-20(29)-en-23,28-dioic acid -28-O-beta-D-glucopyranosyl ester (2) and luteolin-7-O-alpha-L-arabinopyranosyl-6-C-beta-glucopyranoside (3) by spectroscopic methods such as 1D and 2D NMR, HR-ESI-MS and FAB-MS.     

New triterpenoids from the leaves of Abrus precatorius

Three new (1-3) triterpenoids and one known (4) triterpenoid were isolated from an acid hydrolyzed methanol-soluble extract of the leaves of Abrus precatorius. Their structures were identified as (20S,22S)-3beta,22-dihydroxycucurbita-5(10),24-diene-26,29-dioic acid delta-lactone (1), 3-O-[6'-methyl-beta-D-glucuronopyranosyl]-3beta,22beta-dihydroxyolean-12-en-29-oic acid methyl ester (2), 3-O-beta-D-glucuronopyranosylsophoradiol methyl ester (3), and sophoradiol (4) by spectroscopic techniques including 2D NMR.     

Practical synthesis of wybutosine, the hypermodified nucleoside of yeast phenylalanine transfer ribonucleic acid

An improved synthesis of 3-beta-D-ribofuranosylwybutine (2) has been achieved by the Wittig reaction between 4,6-dimethyl-9-oxo-3-[2,3,5-tris-O-(tert-butyldimethylsilyl)-beta-D-ribofuranosyl]-4,9-dihydro-3H-imidazo[1,2-a]-purine-7-carbaldehyde (8) and the phosphorane derived from (R)-2-[(methoxycarbonyl)amino]-3-(triphenylphosphonio)propanoate (9), followed successively by methylation, hydrogenation, and deprotection. On the other hand, the minor nucleoside wybutosine of yeast tRNA(Phe) was isolated on a scale of 80 microg by partial digestion of unfractionated tRNA (1 g) with nuclease P1, followed successively by reversed-phase column chromatography, complete digestion with nuclease P1/alkaline phosphatase, and reversed-phase HPLC. Comparison of this nucleoside with 2 has unambiguously established that the structure of wybutosine is (alphaS)-alpha-[(methoxycarbonyl)-amino]-4,6-dimethyl-9-oxo-3-beta-D-ribofuranosyl-4,9-dihydro-3H-imidazo[1,2-a]purine-7-butanoic acid methyl ester (2).     

Triterpenes and saponins from Ilex psammophila

Two new saponins were isolated from the leaves of Ilex psammophila. Their structure was established by chemical and spectroscopic methods as 28-O-beta-D-glucopyranosylester of 20(S)-ilexgenin A ([structure: see text]) and 28-O-beta-D-glucopyranosylester of 20(S)-3beta,19alpha,24-trihydroxyurs-12-ene-23, 28-dioic acid ([structure: see text]).     

Synthesis and Crystal Structure of 2-Fluoro-4-methyl-3-oxo-4-aza-5α-androst-1-ene-17β-carboxylic Acid Methyl Ester

Synthesis and Crystal Structure of 2-Fluoro-4-methyl-3-oxo-4-aza-5α-androst-1-ene-17β-carboxylic Acid Methyl EsterAuthorJANG Yin-Zhi XIANG Zuo LIANG Da-Wei (Department of Applied Chemistry, Zhejiang Sci-Tech. University, Hangzhou 310018, China)AbstractThe title compound VII, 2-fluoro-4-methyl-3-oxo-4-aza-5α-androst-1-ene-17β-carboxylic acid methyl ester (C21H30FNO3, Mr = 363.46), was prepared through a seven-step reaction from pregnenolone, and characterized by elemental and single-crystal X-ray diffraction analyses as well as IR, MS and 1H-NMR spectra. It is of monoclinic system, space group P21/c with a = 6.3882(7), b = 9.9033(11), c = 15.4925(17) , β = 91.923(2)°, V = 979.57(19) 3, Z = 2, Dc = 1.232 mg/m3, μ = 0.088 mm-1, F(000)= 392, R = 0.0465, wR = 0.0989 and λ(MoKα) = 0.71073 . The structure indicates that the four cycles (A: C(1)-C(2)-C(3)-N(1)-C(5)-C(10), B: C(5)-C(6)-C(7)- C(8)-C(9)-C(10), C: C(8)-C(14)-C(13)-C(12)-C(11)-C(9), D: C(14)-C(15)-C(16)-C(17)-C(13)) are in chairand trans-configurations. The results of crystal structure determination show that there exist weak intra-molecular hydrogen bonds, resulting in a two-dimensional supramolecular frame-work of the title compound.Keywordsfluoro-sterol, synthesis, crystal structure, supramolecule     

Synthesis and molecular structure of the methyl ester of 3-bromo-2-(2-hydroxy-2-propyl)-7-oxo-7H-selenolo[2,3-<Emphasis Type="Italic">f</Emphasis>]chromene-8-carboxylic acid

A two-stage method has been developed for the synthesis of the methyl ester of 3-bromo-2-(2-hydroxy-2-propyl)-7-oxo-7H-selenolo[2,3-f]chromene-8-carboxylic acid – a new example of a class of selenophene-containing polycyclic heterocycles. The molecular structure was confirmed by X-ray crystallography.     

Total synthesis of oxidized phospholipids. 3. The (11E)-9-hydroxy-13-oxotridec-11-enoate ester of 2-lysophosphatidylcholine

A total synthesis of (11E)-9-hydroxy-13-oxotridec-11-enoate ester of 2-lysophosphatidylcholine (HOT-PC) was devised to facilitate identification of this oxidized phospholipid. A lactone, 8-(3-oxo-1H,6H-2-oxinyl)octanoic acid (1), believed to be generated through an intermediate (11E)-9-hydroxy-13-oxotridec-11-enoic acid (HOT), is produced upon autoxidation of linoleic acid. A synthesis of lactone 1 methyl ester was accomplished from HOT involving a novel trans-cis isomerization that is driven to completion by cyclization to a hemiacetal. An alternative route to this carbon skeleton was also achieved that provides the lactone 1 itself.