Spirolactone Ring Research Articles

Determination of Mercuric Ion in Water Samples with a LED Exciting and CCD Based Portable Spectrofluorimeter

The fluorescent characteristics of a fluorimetric chemosensor for mercuric ion, Hg2+, employing a synthesized Rhodamine 6G derivative, have been analyzed. For that, a portable spectrofluorimeter composed of a 515 nm LED as excitation source, two fiber-optics and a CCD camera as detector, has been used, intended for “in situ” analysis. A highly selective Rhodamine based probe for Hg2+, that is water soluble and gives a positive response upon analyte binding, is reported. The reagent is bearing a monothiospirolactone group in a Rhodamine 6G architecture and the thiol atom served for the direct attack of thiophilic Hg2+. The fluorescence enhancement is attributed to the spirolactone ring opening and the coordination of two sulphur atoms to Hg2+ giving a 2:1 reagent: Hg2+ stoichiometry complex.

ChemInform Abstract: An Improved Synthesis of Dioxindole-3-propionic Acid and Some Transformations of the C-3 Hydroxyl Group.

Dioxindole-3-propionic acid lactone (3) is obtained in 80% yield by oxidative cyclization of indole-3-propionic acid with t-BuBr/DMSO. In the presence of 18-crown-6 in DMSO, KCN opens the spirolactone ring of 3 at C-3 with the formation of 3-cyanooxindole-3-propionic acid (4a) in 14% yield. Methanolysis of the lactone is strongly promoted by DMAP, and the resulting 3-hydroxy ester (5) is converted into the 3-fluoro ester (6) with methyl DAST. Every attempt to isolate 3-fluorooxindole-3-propionic acid resulted in rapid intramolecular displacement of fluorine by the free carboxyl group to reform the spirolactone. The 3-hydroxy ester is converted into the 3-chloro ester (9) with SOCl 2 /Et 3 N. The halogen is readily displaced by nucleophiles (e.g., N 3 − , CN − , NH 3 , AcO − , H 2 O) to generate the corresponding methyl 3-X-oxindole-3-propionate

A new phenanthrene with a spirolactone from Dendrobium chrysanthum and its anti-inflammatory activities

Investigation of phenolic patterns from the stems of Dendrobium chrysanthum by HPLC–PDA–MS has led to the isolation of a new phenanthrene derivative with a spirolactone ring, dendrochrysanene ( 1), that proved to suppress the mRNA level of TNF-α, IL8, IL10, and iNOS in murine peritoneal macrophages. The structure of 1 was characterized on the basis of various NMR ( 1H, 13C, 1H– 1H COSY, HMQC, and HMBC), mass spectrometry, and X-ray crystal diffraction data.

Lambertellols A and B, Novel 3,4‐Dihydronaphthalen‐1(2H)‐ones with Spiro‐butenolide Produced by Lambertella sp. 1346.

AbstractFor Abstract see ChemInform Abstract in Full Text.

Lambertellols A and B, novel 3,4-dihydronaphthalen-1(2H)-ones with spiro-butenolide produced by Lambertella sp.1346.

[structure: see text] Lambertella sp. 1346 was found to produce lambertellols A (1) and B (2) carrying a novel dihydronaphthalen-1(2H)-ones with spiro-1-furan-2(5'H)-one. The spiro-lactone ring moiety of both 1 and 2 were easily migrated to afford lambertellin, a known metabolite of Lambertella corni-maris. The absolute stereochemistry of these compounds was established on the basis of CD spectrum after chemical derivatization.

Norlanostane and Lanostane Glycosides from the Bulbs of Chionodoxa luciliae and Their Cytotoxic Activity.

AbstractFor Abstract see ChemInform Abstract in Full Text.

Norlanostane and lanostane glycosides from the bulbs of Chionodoxa luciliae and their cytotoxic activity.

Ten lanostane glycosides (1-10), including two new norlanostane glycosides (2 and 7) and a new lanostane glycoside with a spirolactone ring system (9), were isolated from the fresh bulbs of Chionodoxa luciliae (Liliaceae). The structures of the new compounds were determined on the basis of extensive spectroscopic analysis and the results of hydrolytic cleavage to be (23S)-3beta-[(O-beta-D-apiofuranosyl-(1-->2)-O-[beta-D-glucopyranosyl-(1-->3)]-O-beta-D-glucopyranosyl-(1-->2)-alpha-L-arabinopyranosyl-(1-->6)-beta-D-glucopyranosyl)oxy]-17alpha,23-epoxy-28,29-dihydroxy-27-norlanost-8-en-24-one (2), (23S)-17alpha,23-epoxy-29-hydroxy-3beta-[(O-alpha-L-rhamnopyranosyl-(1-->2)-O-[O-beta-D-glucopyranosyl-(1-->2)-beta-D-glucopyranosyl-(1-->3)]-O-beta-D-glucopyranosyl-(1-->2)-alpha-L-arabinopyranosyl-(1-->6)-beta-D-glucopyranosyl)oxy]-27-norlanost-8-ene-15,24-dione (7), and (23S,25R)-17alpha,23-epoxy-29-hydroxy-3beta-[(O-alpha-L-rhamnopyranosyl-(1-->2)-O-[beta-D-glucopyranosyl-(1-->3)]-O-beta-D-glucopyranosyl-(1-->2)-alpha-L-arabinopyranosyl-(1-->6)-beta-D-glucopyranosyl)oxy]lanost-8-en-23,26-olide (9), respectively. The cytotoxic activity of the isolated compounds against HSC-2 human oral squamous cell carcinoma cells are also reported.

Stypolactone, an interesting diterpenoid from the brown alga Stypopodium zonale

A new diterpenoid of mixed biogenesis, stypolactone 8 , containing a tricyclic terpenoid moiety which in combination with its spirolactone ring, leads to a novel carbon skeleton, has been isolated from the brown alga Stypopodium zonale. It's structure and relative stereochemistry were established by spectroscopic evidence and biogenetic considerations.

Blespirol, a phenanthrene with a spirolactone ring from Bletilla striata

A novel phenanthrene derivative with a spirolactone ring, blespirol, has been isolated from tubers of Bletilla striata and its structure elucidated on the basis of spectroscopic data and X-ray analysis.

Synthesis and Photochemistry ofsyn- andanti-9,10-Epoxy-1, 4-dihydro-1,4-ethanonaphthalene-2,3-diones

The title epoxydiketones were prepared stereoselectively, direct epoxidation of 3a-c with MCPBA produced syn isomers la-c whereas epoxidation of 4a-d followed by saponification of the spirolactone rings gave anti isomers 2a-c. The stereochemistry of 1a and 2a was established by X-ray diffraction, whereas that of the remaining epoxydiketones was determined from the correlation of visible, 1H, and 13C NMR spectral data; the differences between spectra of the corresponding syn and anti isomers are explained in terms of through-space interaction and steric effects. Photolysis of syn isomers 1a-c afforded the corresponding naphthalenes 8a-c in almost quantitative yields; in contrast, irradiation of anti isomers 2a-c gave complicated mixtures. The quantum yield of disappearance of 1a was 52 times that of 2a. Reaction mechanisms are proposed to account for the product formation. The differences in the photochemical behavior of the title syn and anti isomers are rationalized in terms of stereoelectronic effects of the epoxy rings in the syn isomers.

An improved synthesis of dioxindole-3-propionic acid and some transformations of the C-3 hydroxyl group

Dioxindole-3-propionic acid lactone (3) is obtained in 80% yield by oxidative cyclization of indole-3-propionic acid with t-BuBr/DMSO. In the presence of 18-crown-6 in DMSO, KCN opens the spirolactone ring of 3 at C-3 with the formation of 3-cyanooxindole-3-propionic acid (4a) in 14% yield. Methanolysis of the lactone is strongly promoted by DMAP, and the resulting 3-hydroxy ester (5) is converted into the 3-fluoro ester (6) with methyl DAST. Every attempt to isolate 3-fluorooxindole-3-propionic acid resulted in rapid intramolecular displacement of fluorine by the free carboxyl group to reform the spirolactone. The 3-hydroxy ester is converted into the 3-chloro ester (9) with SOCl 2 /Et 3 N. The halogen is readily displaced by nucleophiles (e.g., N 3 − , CN − , NH 3 , AcO − , H 2 O) to generate the corresponding methyl 3-X-oxindole-3-propionate

Synthesis of 6,9‐Dipropyl‐1,4‐Dioxaspiro[4.5] Deca‐6,8‐Diene‐2,10‐Dione and its Diels‐Alder Reactions with Substituted Acetylenes

AbstractThe title compound, a masked 3,6‐di‐n‐propyl‐o‐benzoquinone, was synthesized from 3,6‐di‐n‐propylcatechol in 82% yield. Its Diels‐Alder reactions with methyl propiolate, phenylacetylene, 1‐octyne, dimethyl acetylenedicarboxylate, diphenylacetylene and 3‐hexyne were studied. The yields of the adducts were excellent except for the last two cases in which the unimolecular decomposition of the title compound to generate 3,6‐di‐n‐propylcatechol methylene ether predominates. The regiochemistry of the adducts derived from monosubstituted acetylenes were determined by the correlation of 13C chemical shifts of the adducts and the corresponding bicyclo[2.2.2]octa‐5,7‐diene‐2,3‐diones obtained from the hydrolysis of the spirolactone ring of the Diels‐Alder adducts. Photolysis of these α‐diketones gave the corresponding aromatic compounds in high yields. These synthetic sequences provide an effective entry to bicyclo[2.2.2]octa‐5,7‐diene‐2,3‐diones and polysubstituted benzene derivatives.

Syntheses of steroids having a bakkenolide-type spirolactone ring. I. Synthesis of 4'-methylenedihydrospiro-(5.ALPHA.-cholestane-3,3'(2'H)-furan)-2'-one.

Syntheses of steroids having a bakkenolide-type spirolactone ring. I. Synthesis of 4'-methylenedihydrospiro-(5.ALPHA.-cholestane-3,3'(2'H)-furan)-2'-one.