REACTIONS OF OZONIDES: III. OZONOLYSIS OF ETHYL 10-UNDECENOATE IN ETHANOL

1965 ◽  
Vol 43 (2) ◽  
pp. 319-327 ◽  
Author(s):  
D. G. M. Diaper ◽  
D. L. Mitchell
Keyword(s):  
Sebacic Acid ◽  
Major Product ◽  
Alkyl Ester ◽  
Similar Treatment ◽  
Oxidative Esterification ◽  
Temperature Range ◽  
Ester Formation ◽  
Minor Degree ◽  
A Minor ◽  
Undecenoic Acid

Diethyl sebacate was the major product obtained by ethanolysis of the ozonization products of ethyl 10-undecenoate in the temperature range 28 to 170 °C. Mixed esters of sebacic acid were similarly obtained, in poor to moderate yields, by alcoholysis of the ozonization product from an alkyl ester of 10-undecenoic acid in the appropriate alcohol. Sebacic acid half esters are prepared by a similar treatment of the ozonization products from 10-undecenoic acid itself. Ester formation has been shown to proceed mainly by rearrangement of an alkoxyhydroperoxide, with oxidative esterification of an aldehyde intermediate contributing to a minor degree.

Synthesis of some bicyclo[2.2.2]oct-5-en-2-ones and bicyclo[2.2.2]octan-2-ones. Rearrangements accompanying oxidative decarboxylation with lead tetraacetate

1981 ◽  
Vol 59 (2) ◽  
pp. 344-355 ◽  
Author(s):  
Peter Yates ◽  
Gordon E. Langford
Keyword(s):  
Dicarboxylic Acid ◽  
Acyl Migration ◽  
Dicarboxylic Acids ◽  
Acid Group ◽  
Major Product ◽  
Lead Tetraacetate ◽  
Oxidative Decarboxylation ◽  
Similar Treatment ◽  
Carbonium Ion ◽  
A Minor

1-Methoxy-2-methyl-1,4-cyclohexadiene (3), 2-methoxy-1-methyl-1,3-cyclohexadiene (2), and 2-methoxy-1,5,5-trimethyl-1,3-cyclohexadiene (14) on heating with maleic anhydride give 1-methoxy-endo-7-methylbicyclo[2.2.2]oct-5-ene-syn-2,3-dicarboxylic acid anhydride (7) and its 6-methoxy-1-methyl (16a) and 6-methoxy-1,8,8-trimethyl (16b) analogues, respectively. On hydrolysis 16a and 16b give the corresponding keto dicarboxylic acids, 18a and 18b, via keto anhydrides 17a and 17b. Treatment of 18b with lead tetraacetate gives 1,8,8-trimethylbicyclo[2.2.2]oct-5-en-2-one (19) together with products in which rearrangement to a bicyclo[3.2.1]octane system has occurred. Treatment of 17b with bis(triphenylphosphino)nickel dicarbonyl gives only 19; similar treatment of 17a gives 1-methylbicyclo[2.2.2]oct-5-en-2-one (1). Reaction of bicyclo[2.2.2]octane-2,3-dione (27) with methyllithium gives 3-hydroxy-3-methylbicyclo[2.2.2]octan-2-one (28), its dimer 31, and a diol 30. Treatment of 5-exo-acetoxy-1, 5-endo-dimethyl-6-oxobicyclo[2.2.2]octane-anti-2,3-dicarboxylic acid (37) with lead tetraacetate gives 3-endo-acetoxy-1,3-exo-dimethyl-bicyclo[2.2.2]oct-5-en-2-one (33) as a minor product; the major product is derived by rearrangement to a bicyclo[3.2.1]octane system. It is proposed that this rearrangement, like that of 18b, involves oxidative decarboxylation of a single carboxylic acid group to give a carbonium ion that undergoes rearrangement via a 1,2-acyl migration.

Platelet Incorporation of Labelled Adenosine and Adenosine Diphosphate

1969 ◽  
Vol 22 (02) ◽  
pp. 304-315 ◽  
Author(s):  
E. W Salzman ◽  
T. P Ashford ◽  
D. A Chambers ◽  
Lena L. Neri
Keyword(s):  
Platelet Rich Plasma ◽  
Adenosine Diphosphate ◽  
Platelet Inhibition ◽  
Electron Microscopic ◽  
Platelet Binding ◽  
Minor Degree ◽  
A Minor ◽  
Plasma Marker ◽  
Electron Microscopic Radioautography ◽  
Simultaneous Assessment

SummaryAfter incubation of platelet-rich plasma with labelled adenosine or ADP, platelet incorporation of radioactivity was assessed. Platelets were rapidly separated for counting by filtration through cellulose acetate Millipore. Inulin-H3 served as a plasma marker, and triple isotope techniques permitted simultaneous assessment of the behavior of the adenine and phosphate moieties of ADP without washing of platelets. In other experiments, electron microscopic radioautography was employed to trace the label after platelet incorporation.The results were consistent with previous reports that ADP is dephosphorylated in plasma and is incorporated by platelets only as a dephosphorylated residue, probably adenosine. The label crossed the platelet membrane and entered the platelet, where it was distributed in platelet granules and the agranular cell sap. Concentration within granules occurred to a minor degree.The results support the hypothesis that platelet aggregation by ADP occurs without a persistent bond of ADP to the platelet. Inhibition of aggregation by adenosine probably depends on a metabolic or transport process rather than on competition between adenosine and ADP for platelet binding sites.

Selective O-Methyloxime Formation From 6-Methoxy-2-[(1'-methyl-2',5'-dioxocyclopentyl)-methyl]-3,4-dihydronaphthalen-1(2H)-one

1994 ◽  
Vol 47 (4) ◽  
pp. 649 ◽  
Author(s):  
DJ Collins ◽  
GD Fallon ◽  
CE Skene
Keyword(s):  
Lithium Aluminium Hydride ◽  
X Ray ◽  
X Ray Crystallography ◽  
Lithium Aluminium ◽  
Major Isomer ◽  
Toluenesulfonic Acid ◽  
Ester Formation ◽  
Diastereomeric Mixture ◽  
A Minor

Reaction of 6-methoxy-2-[(1′-methyl-2′,5′-dioxocyclopentyl)methyl]-3,4-dihydronaphthalen-1(2H)-one (4a) with 1 or 2 moles of O- methylhydroxylamine hydrochloride in pyridine gave (1′SR,2RS)-6-methoxy-2-[(1′-methyl-2′,5′-dioxocyclopentyl)methyl]-3,4-dihydronaphthalen-1(2H)-one (E)-2′-O-methyloxime (5a), or the corresponding 2′,5′-bis(O-methyloxime ) (6), respectively. A minor product from the formation of the bis (O- methyloxime ) (6) was the (Z) isomer (5b) of the mono(O- methyloxime ) (5a); the structure and stereochemistry of (5a) and (5b) were established by X-ray crystallography. Reduction of the keto bis (O-methyloxime ) (6) with 0.25 mole of lithium aluminium hydride gave a diastereomeric mixture of the corresponding alcohols (7a), of which the major isomer was characterized by ester formation. The bis (O-methyloxime ) (6) could be hydrolysed to the parent triketone (4a), but it resisted deprotection with cetyltrimethylammonium permanganate. Reaction of the triketone (4a) with 1 mole of 4-anisidine in the presence of 4-toluenesulfonic acid resulted in retro Michael cleavage with formation of 3-(4′-methoxyphenyl)amino-2-methylcyclopent-2-en-1-one (1).

Nucleophilic addition at u 3 -alkyne clusters leading to carbon-carbon bond formation

1982 ◽  
Vol 308 (1501) ◽  
pp. 59-66 ◽  
Keyword(s):  
Bond Formation ◽  
Organic Ligand ◽  
Major Product ◽  
Unsaturated Hydrocarbon ◽  
Terminal Alkynes ◽  
Hydrogen Atoms ◽  
Metal Atoms ◽  
Carbon Carbon Bond ◽  
Anionic Species ◽  
A Minor

Reactions of nucleophiles with triosmium carbonyl clusters, especially those containing unsaturated hydrocarbon ligands, are discussed. Attack may be at CO, the metal atoms, at carbon of the organic ligand, or, where there are acidic metal-bound hydrogen atoms, deprotonation to give anionic clusters may occur. New results on the reactions of LiBHEt3 with p3-alkyne clusters of type Os3(CO)10 (RC2R') are considered in the light of the range of possible sites of attack. Protonation of anionic species that are formed gives hydrogenation products with or without the loss of CO. Os3H2(CO)9(RC2R') is usually a minor product, while C-C coupling leads to Os3H(CO)9(CRCR'COH) (in general the major product) and to Os3H(CO)9- (CRCR'CH). With terminal alkynes RC2H H-atom transfer accompanies C-C coupling to give Os3H(CO)9(RC—C =C H 2) in substantial amounts. The initial site of hydride attack (CO, alkyne or metal) is considered in the context of low-temperature 1H n.m.r. results.

The dissolution of beryllia in molten alkali metal hydroxides

1965 ◽  
Vol 18 (11) ◽  
pp. 1719 ◽  
Author(s):  
ME Shying ◽  
RB Temple
Keyword(s):  
Alkali Metal ◽  
Water Vapour ◽  
Beryllium Oxide ◽  
Major Product ◽  
Kcal Mole ◽  
Metal Hydroxides ◽  
Temperature Range ◽  
Alkali Metal Hydroxides ◽  
Reversible Formation

Beryllium oxide shows a limited reversible solubility in molten alkali-metal hydroxides only when dissolved water vapour is present. The reaction taking place has been studied in detail. The results obtained are consistent with the reversible formation of the beryllate ion [Be(OH)4]2- as the major product, according to the overall equation BeO(solid) + H2O(dissolved) + 2OH- ↔ [Be(OH)4]2-(dissolved) The enthalpy of the reaction has been calculated to be 4.8 kcal/mole over the temperature range 240-510�.

Isolation of radioactive iodothyronines for kinetic studies: a comparison of two methods

1982 ◽  
Vol 99 (1) ◽  
pp. 64-71 ◽  
Author(s):  
Jens Faber ◽  
lb Bo Lumholtz ◽  
Carsten Kirkegaard ◽  
Kaj Siersbæk-Nielsen ◽  
Thorkild Friis
Keyword(s):  
Radioactive Iodine ◽  
Single Injection ◽  
Kinetic Studies ◽  
Acid Precipitation ◽  
Relative Difference ◽  
Metabolic Clearance ◽  
Metabolic Clearance Rate ◽  
Minor Degree ◽  
A Minor

Abstract. A method based on the principle of gel separation followed by antibody extraction (GSAE) has been developed for isolation of radioactive thyroxine (T4), 3,5,3'-triiodothyronine (T3), 3,3',5'-triiodothyronine (rT3), 3,3'-diiodothyronine (3,3'-T2), 3',5'-diiodothyronine (3',5'-T2) and 3'-monoiodothyronine (3'-T1) in serum. This method was used for the estimation of the metabolic clearance rate (MCR) of the iodothyronines using the single injection, non-compartmental approach, and was compared to the conventional trichloroacetic acid precipitation/ethanol extraction (TCA-E) technique. The GSAE method excluded the co-determination of radioactive iodine and iodoproteins, whereas the co-determination of radiolabelled daughter iodothyronines was found negligible. The relative difference of duplicate estimations of MCR was approximately 10%. Using the TCA-E method for isolation of tracer, the MCR of T4, T3 and rT3 was underestimated to a minor degree (20%), whereas the MCRs of 3,3'-T2, 3',5'-T2 and 3'-T1 were 20–40% of those estimated by the GSAE method. In conclusion the GSAE method was found suitable for kinetic studies of iodothyronines, whereas the TCA-E method cannot be used for turnover studies of 3,3'-T2, 3',5'-T2 or 3'-T1.

Base-catalyzed Degradations of Carbohydrates. IV. Formation of 2,3-Anhydro-2-methoxy-α-D-allopyranose Derivatives from 3-Deoxy-D-erythro-hex-2-enopyranoses

1973 ◽  
Vol 51 (3) ◽  
pp. 394-401 ◽  
Author(s):  
G. O. Aspinall ◽  
R. R. King
Keyword(s):  
Spectroscopic Data ◽  
Kojic Acid ◽  
Major Product ◽  
A Minor

1,4,6-Tri-O-acetyl-3-deoxy-2-O-methyl-α-D-erythro-hex-2-enopyranose (4) reacts with m-chloroperbenzoic acid to give the epoxide, 1,4,6-tri-O-acetyl-2,3-anhydro-2-methoxy-α-D-allopyranose (6), as the major product together with the perester, 4,6-di-O-acetyl-1,2-O-(1′-m-chloroperbenzoyloxy-ethylidene)-2-methoxy-α-D-glucopyranose (5), as a minor product. The structures of these novel compounds have been assigned on the basis of spectroscopic data and of transformations (i) to kojic acid diacetate and (ii) by oxidative degradations to substituted aldopentonolactones. Further examination of the products of the reaction of 1-O-acetyl-3-deoxy-2,4,6-tri-O-methyl-α-D-erythro-hex-2-enopyranose (1) with m-chloroperbenzoic acid has shown that the epoxide, 1-O-acetyl-2,3-anhydro-2-methoxy-4,6-di-O-methyl-α-D-allopyranose (15), is formed in addition to the previously characterized perester 2.

THE EFFECTS OF TOBACCO SMOKING IN CHILDREN

PEDIATRICS ◽  
1967 ◽  
Vol 40 (3) ◽  
pp. 362-362
Author(s):  
T. E. C.
Keyword(s):  
American Medical Association ◽  
Medical Association ◽  
American Medical ◽  
Tobacco Smoking ◽  
Organic Lesion ◽  
Minor Degree ◽  
Normal Quantity ◽  
Continued Use ◽  
A Minor

The very first issue of the Journal of the American Medical Association contained the following abstract of a paper published originally in the French Revue d'Hygiene of March 20, 1883 on the evil effects of tobacco smoking in children. Dr. G. Decaisne, in a paper read before the Paris Société de Médicine Publique, gives observations upon thirty-eight children, between nine and fifteen years of age, where decided effects [due to smoking] were produced in twenty-seven. Twenty-two had disturbances of the circulation, bruit de souffle in the carotids, palpitation of the heart, difficulty in digestion, indolent intelligence and a decided taste for strong drinks. Thirteen had an intermittent pulse. Eight showed a notable diminution of blood corpuscles. Twelve had frequent attacks of nosebleed. Ten were restless in their sleep with nightmares. Two showed slight ulcerations of the buccal membrane, which disappeared promptly on their giving up smoking for a few days. In one case pulmonary phthisis seemed to have resulted from a profound alteration of the blood due to the long continued use of tobacco. In eleven children who gave up smoking entirely, with six these symptoms disappeared in less than six months; three still suffered in a minor degree at the end of a year. He concludes, as the result of his observations collected through twenty years, that the pernicious effects of smoking upon children are incontestable. That it produces intermittence of the pulse, alteration of the blood, and the principal symptoms of chloroanemia, pallor of the countenance, emaciation, bruit de souffle in the carotids, palpitation of the heart, diminution of the normal quantity of the blood corpuscles, and difficulties of digestion. That the mental faculties become sluggish, with a fondness for strong drinks. That the ordinary treatment for chloroanemia produces no effect while the habit continues, and, finally, that with those children who are without organic lesion, all these disorders disappear promptly and without leaving any traces behind, when the habit is discontinued. Could French tobacco of the 1880's have been all that potent, or was Doctor Decaisne an alarmist?

Bridged-ring steroids. II. The synthesis of bridged steroids with a bicyclo[2.2.1]heptane ring A system

1981 ◽  
Vol 59 (11) ◽  
pp. 1641-1650 ◽  
Author(s):  
Peter Yates ◽  
Françoise M. Winnik
Keyword(s):  
Sodium Borohydride ◽  
Major Product ◽  
Analogous Reaction ◽  
Ene Reactions ◽  
Similar Treatment

Bridged steroids with a bicyclo[2.2.1]heptane ring A system are formed on thermolysis of 5-vinyl 3-keto steroids. 5-Vinyl-5α-cholestan-3-one (26) on being heated at 350 °C in decalin gave 2α,5-(syn-methylmethano)-5α-cholestan-3-one (27). Similar treatment of 17β-hydroxy-5-vinyl-5β-estran-3-one (21) gave 17β-hydroxy-2β,5-(syn-methylmethano)-5β -estran-3-one (30), which was also obtained by reduction of 2β,5-(syn-methylmethano)-5β-estrane-3,17-dione (31) with sodium borohydride on alumina. Compound 31 was formed as the major product on thermolysis of 5-vinyl-5β-estrane-3,17-dione (24) at 350 °C, together with 5-(trans-propenyl)-A-nor-5β-estrane-3,17-dione (32). Compounds 27, 30, and 31 are considered to arise via intramolecular ene reactions of the Δ2-enols of compounds 26, 21, and 24, respectively. Compound 32 is postulated to be formed via an analogous reaction of the Δ3-enol of 24, followed by thermolysis of the resulting 3′-methyl-4β,5-dihydrocyclopropa[4,5]-5β-estrane-3,17-dione (36). Photolysis of 30 in methanol results in α-cleavage of the C2—C3 bond and the formation of a ketene-derived ester and two enal-derived oxetanes.

Transition metal complexes of substituted alkynes. XI. The reactions of But-2-yne and Hexafluorobut-2-yne with Dicarbonyl(η-cyclopentadieny)-cobalt and -rhodium

1974 ◽  
Vol 27 (1) ◽  
pp. 61 ◽  
Author(s):  
RS Dickson ◽  
HP Kirsch
Keyword(s):  
Transition Metal ◽  
Metal Complexes ◽  
Transition Metal Complexes ◽  
Major Product ◽  
Reaction Conditions ◽  
A Minor ◽  
Related Reaction

The thermally initiated reaction of hexafluorobut-2-yne and (q-C5H5)C~(C0)2 gives the 1-4-q- hexakis(trifiuoromethy1)benzene complex (7-C5H5)Co [(CF3C2CF3)3] in addition to the known cyclopentadienone complex (q-C5H5)Co [(CF3C2CF3)2CO]. The related reaction of but-2-yne with (q-CjH j)Co(CO)2 gives several compounds in addition to the cyclopentadienone complex (q-C jHj)C~- [(MeC2Me)2CO] which has been isolated previously from this reaction. Thus, the duroquinone complex (q-C5H5)Co [(MeC2Me)2(C0)2], the maleoyl complex (q-C5H5)Co(MeC2Me)(C0)3, and free duroquinone have been obtained. The yields of the various products are influenced by the reaction conditions. The metallocyclopentadiene complex (q-C jH j)2Rh2(CF3C2CF3)2, which is formed in the reaction between (q-C,H,)Rh(CO), and hexafluorobut-2-yne, exhibits fluxional behaviour in solution at c. 130". Two complexes are formed in the reaction at 100-120' between (q-C5Hj)Rh- (CO)2 and but-2-yne. These are the cyclopentadienone complex (q-C5H5)Rh [(MeC2Me)2CO] and the duroquinone complex (7-CjH5)Rh [(MeC2Me)2(C0)2]. Comparison of the various reactions indicates that: (i) a cyclopentadienone complex (q-CgH5)M- [(MeC2Me)2CO] is generally formed as major product and a duroquinone complex (q-C5Hj)M- [(MeC2Me)2(C0)2] is generally formed as a minor product in reactions between (q-C5H5)M(C0)2, M = Co and Rh, and but-2-yne; and (ii) a tetrahaptobenzene complex (q-C5H5)M [(CF3C2CF3)3] is formed as major product when M = Rh and as a minor product when M = Co in reactions between (q-C5H5)M(CO)2 and hexafluorobut-2-yne.

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