摘要:

AbstractThe preparation of someN,N′‐disubstituted‐5,5′‐diamino‐3,3′‐bi‐1,2,4‐oxadiazoles from dichloroglyoxime diacetate and 1,1,3,3‐tetrasubstituted guanidines is described. Evidence for the structure is given by spectroscopic data and an

ISSN:0165-0513    

DOI:10.1002/recl.19700890202

出版商:WILEY‐VCH Verlag    

年代:1970

数据来源: WILEY

ISSN:0165-0513    

DOI:10.1002/recl.19700890203

出版商:WILEY‐VCH Verlag    

年代:1970

数据来源: WILEY

摘要:

Abstract1‐Alkynyl sulfides and 1‐alkynyl ethers of the type R‐CC‐Y‐R′ (R = H or alkyl, R′ = alkyl and Y = O or S) were converted into β‐alkyl‐thio‐ and β‐alkoxy‐β‐chloro‐acrylic chlorides R′Y‐CClCR‐CO‐Cl by addition of carbonyl dichloride (phosgene).Thecis‐isomers are formed initially [Cl and (COCl)cis], but partial isomerization occurs during work‐up. Configurations were determined by comparison of the NMR data with those of several derivatives of acrylic acid.Relative addition rates have been determined in competition experimen

ISSN:0165-0513    

DOI:10.1002/recl.19700890204

出版商:WILEY‐VCH Verlag    

年代:1970

数据来源: WILEY

摘要:

AbstractOxidation of 3‐hydroxy‐2‐butanone, CH3COCHOHCH3to 2,3‐butanedione, CH3COCOCH3, by ferricenium cations, Fe(C5H5)2⊕, has been studied in acidic 50 vol % aqueous ethanol. At ferricenium ion concentrations above 0.5 × 10−3mole · l−1the rate of reaction is independent of this concentration. Enolization is suggested to be rate determining. The influence of acid concentration and of oxygen h

ISSN:0165-0513    

DOI:10.1002/recl.19700890205

出版商:WILEY‐VCH Verlag    

年代:1970

数据来源: WILEY

摘要:

AbstractThe photochemical nitrosation of (cyclo)alkanes and alkylbenzenes, containing abstractableprimaryorsecondaryhydrogen atoms, witht‐butyl nitrite has been carried out at 0‐5°C using wavelengths around 400 nm. The main products aretrans‐azodioxy compounds (trans‐dimeric nitroso compounds), derived from the solvent and the corresponding oximes in (total) yields, ranging from 55‐80%. At low temperature or with high‐energy light sources it is possible to isolate thecis‐compounds in low yiel

ISSN:0165-0513    

DOI:10.1002/recl.19700890206

出版商:WILEY‐VCH Verlag    

年代:1970

数据来源: WILEY

摘要:

AbstractThe photochemical nitrosation witht‐butyl nitrite of some branched‐chain hydrocarbons, containingtertiaryhydrogen atoms leads to the formation of monomeric nitroso compounds in yields up to 78%, when a special Soxhlet technique is employed. The use of wavelengths around 400 nm is essential for this react

ISSN:0165-0513    

DOI:10.1002/recl.19700890207

出版商:WILEY‐VCH Verlag    

年代:1970

数据来源: WILEY

摘要:

AbstractMonomericprimaryandsecondarynitrosoalkanes have been generated from thetrans‐dimers by heating in solution. The monomers are photochemically and thermally far more reactive than the dimers. They are isomerized to oximes in 90% yield thermally. Photolysis of nitrosocyclohexane with red light leads to the oxime in 60% yield. Photolysis in the presence of oxygen gives nitrocyclohexane as the main product (85%), together with a small amount of cyclohexyl nitrate.Considerable amounts of cyclohexanol are formed by oxidation of the solvent cyclohexane, presumablyviaa nitroxide‐type intermediate.Whent‐butyl nitrite is photolyzed with light in the region of 400 nm and in the presence of oxygen in CFCl3,t‐butyl nitrate is produced in 90% yield, by the action of intermediary NO and NO2r

ISSN:0165-0513    

DOI:10.1002/recl.19700890208

出版商:WILEY‐VCH Verlag    

年代:1970

数据来源: WILEY

ISSN:0165-0513    

DOI:10.1002/recl.19700890209

出版商:WILEY‐VCH Verlag    

年代:1970

数据来源: WILEY

摘要:

AbstractThe density, refractive index, dielectric constant and viscosity of liquid aluminium isopropoxide have been studied.From observations for the liquid at 25°, immediately after heating at 130° and cooling rapidly, an Onsager dipole moment of 1.7‐2.5 D is calculated.During storage the physical properties change slowly. This confirms the occurrence of a molecular rearrangement reaction, which was inferred previously from molecular weight and NMR data. A further indication was obtained by the discovery of a second solid form of aluminium isopropoxide, which melts at 29.5°, whereas we have found also a form with melting point of about 137°, considerably higher than that for normal aluminium isopropoxide, 118°.The rates of changes in density and viscosity have been measured at different temperatures, from which the activation energy for the rearrangement reaction is estimated to be about 12 kca

ISSN:0165-0513    

DOI:10.1002/recl.19700890210

出版商:WILEY‐VCH Verlag    

年代:1970

数据来源: WILEY

摘要:

AbstractThe main sterol ofVernonia anthelminticaseed is 7,(Z)‐24(28)‐stigmastadienol (Ia). Stigmasterol and a C29‐sterol with a conjugated diene system, probably at C8and C14, are also present, whilst GLC data indicate two other components to be 5‐stigmasten‐3β‐ol and 7,22‐stigmastadienol. A correlation of NMR data is given showing the stereochemistry at the ethylidene group of Ia and in rel

ISSN:0165-0513    

DOI:10.1002/recl.19700890211

出版商:WILEY‐VCH Verlag    

年代:1970

数据来源: WILEY