Reaction of 30-nor-18-lupene derivatives with bromine and peracids

1984 ◽  
Vol 49 (1) ◽  
pp. 141-149
Author(s):  
Eva Klinotová ◽  
Jiří Protiva ◽  
Jiří Klinot ◽  
Alois Vystrčil
Keyword(s):  
Acetic Acid ◽  
Double Bond

The reaction of diol I and diacetate IIwith one mole of bromine gives rise, depending on conditions, to isomeric dienes III-V and IX or to derivatives substituted in position 21 (VII, VIII). On reaction of diacetate II with two moles of bromine in acetic acid 21,22-disubstituted compounds XI and XII were obtained. Diene V is the intermediate in the formation of dienes IV and IX and derivatives XI and XII. Epoxidation of the 18(19)-double bond in compounds I and II takes place from the β-side and leads for epoxides XIV and XV.

Synthesis and properties of 1,3-bis(4-nitrophenyl)-1-butene

1980 ◽  
Vol 45 (7) ◽  
pp. 2120-2124 ◽  
Author(s):  
Gabriel Čík ◽  
Anton Blažej ◽  
Kamil Antoš ◽  
Igor Hrušovský
Keyword(s):  
Acetic Acid ◽  
Nitric Acid ◽  
Double Bond ◽  
Fuming Nitric Acid

1,3-Bis(4-nitrophenyl)-1-butene was prepared by nitration of 1,3-diphenyl-1-butene (I) with fuming nitric acid in acetic acid. The double bond in I was protected by addition of bromine which was eliminated after the nitration. The UV, IR and 1H- spectra of the synthesized compounds are interpreted.

Enaminones as Building Blocks In Heterocyclic Synthesis: A New One Pot Synthesis of Polyfunctional Substituted Pyridines

2001 ◽  
Vol 56 (10) ◽  
pp. 1074-1078 ◽  
Author(s):  
Samia Michel Agamy ◽  
Mervat Mohammed Abdel-Khalik ◽  
Mona Hassan Mohamed ◽  
Mohammed Hilmy Elnagdi
Keyword(s):  
Acetic Acid ◽  
Double Bond ◽  
Aromatic Aldehyde ◽  
Michael Addition ◽  
Ammonium Acetate ◽  
Building Blocks ◽  
Heterocyclic Synthesis ◽  
One Pot ◽  
Active Methyl ◽  
Substituted Pyridines

Enaminones react with a variety of active methyl and methylene reagents in presence of ammonium acetate to yield functionally substituted pyridines in good yields. The reaction proceeded via initial Michael addition across the double bond followed by cyclization. The reaction of enaminone with aromatic aldehyde in acetic acid/ammonium acetate afforded the dihydropyridine that was oxidized to the corresponding pyridine.

THE SOLVOLYSIS OF THE ALPHA- AND BETA-3,4,6-TRI-O-ACETYL-D-GLUCOPYRANOSYL CHLORIDES

1955 ◽  
Vol 33 (1) ◽  
pp. 128-133 ◽  
Author(s):  
R. U. Lemieux ◽  
G. Huber
Keyword(s):  
Acetic Acid ◽  
Double Bond ◽  
Positive Charge ◽  
Main Reaction ◽  
Main Reaction Product ◽  
Double Bond Character ◽  
Ionic Reactions ◽  
Oxygen Bond ◽  
Bond Character ◽  
Anomeric Center

3,4,6-Tri-O-acetyl-β-D-glucopyranosyl chloride was found to undergo solvolysis in acetic acid to form 1,3,4,6-tetra-O-acetyl-α-D-glucopyranose as the main reaction product. The much less reactive anomeric α-chloride also appeared to undergo solvolysis with extensive inversion of the anomeric center. It is submitted that the tendencies for inversion obtained in these ionic reactions are due to the conformations imposed on the intermediate ions through distribution of the positive charge to the ring oxygen and the consequent introduction of double-bond character to the carbon-1 to ring-oxygen bond.

The synthesis of Tetracyclo[5,3,1,03,5,04,9]undecan-2-one and the acid-catalysed and reductive cleavages of the cyclopropyl ring

1975 ◽  
Vol 28 (10) ◽  
pp. 2255 ◽  
Author(s):  
DPG Hamon ◽  
GF Taylor
Keyword(s):  
Acetic Acid ◽  
Double Bond ◽  
Liquid Ammonia ◽  
Aqueous Acetic Acid ◽  
Bromide Ion ◽  
Independent Synthesis

Tetracyclo[5,3,1,03,5,04,9]undecan-2-one (2,4-dehydro-5-homoadamantanone) (3) was synthesized by copper-catalysed intramolecular insertion of a diazoketone into a double bond. Acid-catalysed opening of the cyclopropyl ring in aqueous acetic acid cleaved the C3-C4 bond to give a mixture of exo-7-hydroxytricyclo[4,3,1,13,8]undecan-4-one (13) and its acetate (12). Under the same conditions except for the presence of bromide ion, a mixture of (12), (13) and exo-7- bromotricyclo[4,3,1,13,8]-undecan-4-one (17) was obtained. Reduction of (17) with LiAlH4 gave homoadamantanol. Reduction of (3) with lithium in liquid ammonia gave cleavage of the C 3-C 5 bond to afford tricyclo[5,3,1,04,9]-undecan-2-one (4), the structure of which was confirmed by independent synthesis.

Chemical Constituents of Corchorus capsuJaris and C. olitorius (Jute Plant), III. Structure of Corosin

1974 ◽  
Vol 29 (5-6) ◽  
pp. 209-221 ◽  
Author(s):  
M. Manzoor-i-Khuda ◽  
Gerhard Habermehl
Keyword(s):  
Acetic Acid ◽  
Double Bond ◽  
Carbon Atom ◽  
Sulphuric Acid ◽  
Main Product ◽  
Chemical Constituents ◽  
Dioic Acid ◽  
Acetate Ester ◽  
Acid Reagent

Corosin (8; R = R1 = H) has been reisolated through a modified procedure, as its acetate (8; R=H, R1 = Ac), in an overall yield of 0.2% from jute roots. On pyrolysis in vacuo, corosin gave pyro corosin (1a; R1 = OH, R2= COOH, R3 = R5 = H, R4 = R6 = Me), shown to have a 12:18 (17) di-ene formed by elimination of the 19-OH and the angular C-28 carboxyl in the molecule. On rearrangement with concentrated sulphuric acid in acetic acid, corosin acetate gave corosin anhydro lactone acetate (7; R1 = Ac, R = H), having a 13(18) double bond and a lactone bridge between the 28-carboxyl and the 20-carbon atom. Corosin acetate ester (8; R = Me, R 1 = Ac), on treatment with sulphuric-acetic acid reagent, gave as the main product anhydro corosin acetate ester (7; R = Me, R1= A c), with a 12:18(19)-diene. The structure of corosin is proposed to be urs-12-ene-2α, 3β, 19α-trihydroxy-24, 28-dioic acid (8; R = R1= H).

Rubber, Polyisoprenes and Allied Compounds. VIII. The Formation of Dialkyl Sulfide Dihalides, and Its Bearing on the Problem of Determining the Unsaturation of Vulcanized Rubber

1946 ◽  
Vol 19 (2) ◽  
pp. 287-295
Author(s):  
George F. Bloomfield
Keyword(s):  
Zinc Oxide ◽  
Acetic Acid ◽  
Double Bond ◽  
Potassium Iodide ◽  
Sulfur Atom ◽  
Iodine Monochloride ◽  
Vulcanized Rubber ◽  
Dialkyl Sulfide ◽  
Dialkyl Sulfides ◽  
Halogen Acid

Abstract In determining the unsaturation of olefinic sulfides and disulfides by halogenation methods, the addition of halogen to the sulfur atom must be taken into account. The dihalides of dialkyl or dialkenyl sulfides react with aqueous potassium iodide partly to liberate iodine with regeneration of the sulfide, and partly to form halogen acid and dialkyl or dialkenyl sulfoxides. Correction for the latter reaction, which occurs extensively in the presence of alcohol or acetic acid, must be applied before reliable unsaturation values for dialkenyl sulfides can be obtained. With vulcanized rubber and iodine monochloride, the precise magnitude of the correction to be applied is uncertain, but this uncertainty can be removed by using bromine as the additive reagent. Simple rubber-sulfur vulcanizates show a loss of unsaturation corresponding to one double bond per sulfur atom combined up to at least 8 per cent of combined sulfur; vulcanizates accelerated with mercaptobenzothiazole in the presence of zinc oxide exhibit a substantially smaller loss of unsaturation. The dibromides of dialkyl sulfides readily yield a molecule of bromine to olefins, the reaction being practically exclusively additive.

Long-Range Effect of 17-Substituents in 3-Oxo Steroids on 4,5-Double Bond Hydrogenation

1998 ◽  
Vol 63 (10) ◽  
pp. 1528-1542 ◽  
Author(s):  
Romana Šídová ◽  
Karel Stránský ◽  
Alexander Kasal ◽  
Barbora Slavíková ◽  
Ladislav Kohout
Keyword(s):  
Acetic Acid ◽  
Double Bond ◽  
Carboxylic Acids ◽  
Chain Length ◽  
Long Range ◽  
Alkyl Chain ◽  
Platinum Catalyst ◽  
Alkyl Chain Length ◽  
Range Effect ◽  
Bond Hydrogenation

The long-range effect of substituents in the 17-position on the hydrogenation of double bond of the steroidal ∆4-3-ketones in acetic acid on a platinum catalyst is described in a series of testosterone (1) and epitestosterone (5) esters with carboxylic acids of varying alkyl chain length. The ratio 5α- to 5β-products is affected by the nature of substituents in the position 17.

Chemistry of meso-Dimethylaminopropenyl- porphyrins and -bisporphyrins: the Synthesis of Australochlorin, a Benzochlorin Isomer.

1997 ◽  
Vol 50 (5) ◽  
pp. 487 ◽  
Author(s):  
Dmitry V. Yashunsky ◽  
Gelii V. Ponomarev ◽  
A. S. Moskovkin ◽  
Dennis P. Arnold
Keyword(s):  
Acetic Acid ◽  
Double Bond ◽  
Trifluoroacetic Acid ◽  
Membered Ring ◽  
Macrocyclic Complexes ◽  
Exocyclic Double Bond ◽  
Derivatives Of

The nickel(II) complex of meso-dimethylaminoprop-1-enyloctaethylporphyrin (2c) was converted by quaternization and thermolysis into a pair of novel isomeric macrocyclic complexes (3) and (4). These have a fused six-membered ring, and an exocyclic double bond on the neighbouring β-position, and have been named ‘australochlorins’. Heating these compounds in acetic acid leads to the known nickel(II) octaethylbenzochlorin (1) and a novel β-(1-acetoxyethyl)benzochlorin (5). Trifluoroacetic acid promotes the regioselective formation of benzochlorin/porphyrin species from the mononickel(II) complexes of the acrolein derivatives of bis(octaethylporphyrinyl)ethane and trans-ethene.

Ectodesmata as Revealed By Freeze-Etch Preparations of Plant Epidermal Cell Walls

1973 ◽  
Vol 31 ◽  
pp. 468-469
Author(s):  
N.C. Lyon ◽  
W. C. Mueller
Keyword(s):  
Electron Microscopy ◽  
Acetic Acid ◽  
Nitric Acid ◽  
Oxalic Acid ◽  
Light Microscopy ◽  
Epidermal Cell ◽  
Cell Walls ◽  
Plant Viruses ◽  
Plant Leaves ◽  
Thin Sections

Schumacher and Halbsguth first demonstrated ectodesmata as pores or channels in the epidermal cell walls in haustoria of Cuscuta odorata L. by light microscopy in tissues fixed in a sublimate fixative (30% ethyl alcohol, 30 ml:glacial acetic acid, 10 ml: 65% nitric acid, 1 ml: 40% formaldehyde, 5 ml: oxalic acid, 2 g: mecuric chloride to saturation 2-3 g). Other workers have published electron micrographs of structures transversing the outer epidermal cell in thin sections of plant leaves that have been interpreted as ectodesmata. Such structures are evident following treatment with Hg++ or Ag+ salts and are only rarely observed by electron microscopy. If ectodesmata exist without such treatment, and are not artefacts, they would afford natural pathways of entry for applied foliar solutions and plant viruses.

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