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1. |
Trans‐substitution and equilibration of phenols: Part I. Trans‐t‐butylation of phenols in the presence of aluminum phenoxide type catalysts |
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Recueil des Travaux Chimiques des Pays‐Bas,
Volume 90,
Issue 1,
1971,
Page 5-13
F.R.J. Willemse,
J. Wolters,
E.C. Kooyman,
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摘要:
AbstractPhenols containing a freeortho‐position can be alkylated byortho‐t‐butyl‐phenols in the presence of catalytic amounts of aluminium phenoxide at temperatures between about 120° and 170°.Using 2‐t‐butylphenol, 2,6‐di‐t‐butyl‐phenol or ‐p‐cresol as the alkylating agent, trans‐t‐butylations were carried out with the following phenolic acceptors: phenol,o‐,m‐,p‐cresol,p‐Br‐,p‐Cl‐,p‐F‐,p‐CH3O‐,p‐t‐Bu‐,p‐isoPr‐, andp‐Et‐phenol. Higher rates were observed for the more acidic phenols.The above mentioned reactions lead to equilibria of the type: 2,6‐di‐t‐butyl‐p‐Z‐C6H2OH +p‐Z‐C6H4OH ⇄ 2 2‐t‐butyl‐p‐Z‐C6H3OHThe equilibrium constant for this reaction is about 24 and independent of the substituent in the phenolic nucleus.For Z = CH3the energy of activation has the value 36 (± 3) kcal/mole.When the 3, 4 and 5 positions are unoccupied, a slowortho‐paraisomerization takes place along withortho‐trans‐t‐butylation.The equilibrium between 2‐t‐butylphenol and 4‐t‐butylphenol lies far towards the thermodynamically more stablepara‐isomer, theortho‐isomer however is kinetically more favourable.Meta‐isomers are formed under these conditions to a small extent and only after long reaction times.At temperatures above 140° some dealk
ISSN:0165-0513
DOI:10.1002/recl.19710900102
出版商:WILEY‐VCH Verlag
年代:1971
数据来源: WILEY
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2. |
Trans‐substitution and equilibration of phenols: Part II. Trans‐t‐butylation of phenols in the presence ofpara‐toluenesulfonic acid as the catalyst |
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Recueil des Travaux Chimiques des Pays‐Bas,
Volume 90,
Issue 1,
1971,
Page 14-20
F.R.J. Willemse,
J. Wolters,
E.C. Kooyman,
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摘要:
AbstractPhenols containing a freeorthoposition can be alkylated byortho‐t‐butyl‐phenols in the presence of catalytic amounts ofp‐toluenesulfonic acid at temperatures between ∼ 60 and 100°.Using,e.g., 2,6‐di‐t‐butyl‐p‐cresol as an alkylating agent, trans‐t‐butylations were carried out with a number ofpara‐ andortho‐substituted phenols.The above mentioned reactions lead to equilibria of the type: 2,6‐di‐t‐butyl‐p‐ZC6H2OH +p‐ZC6H4OH ⇄ 2 (2‐t‐butyl‐p‐ZC6H3OH)The equilibrium constant (K= 43 at 80°C) is independent of the substituent present in the phenolic nucleus.For Z =p‐CH3the energy of activation of the forward reaction amounts to 18.5 kcal/mole.Ortho‐paraisomerization occurs, when the 3, 4 and 5 positions are free. Several differences between the catalytic effects o
ISSN:0165-0513
DOI:10.1002/recl.19710900103
出版商:WILEY‐VCH Verlag
年代:1971
数据来源: WILEY
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3. |
Sulfur compounds in free radical reactions. Part IV. Induced decomposition of arenediazothiolates |
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Recueil des Travaux Chimiques des Pays‐Bas,
Volume 90,
Issue 1,
1971,
Page 21-26
H. van Zwet,
J. Reiding,
E.C. Kooyman,
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摘要:
AbstractProduct distributions and rate data of the thermal decomposition of a diazothiolate (Ar‐NNSR) in benzene, chlorobenzene and nitrobenzene as a function of initial diazothiolate concentrations show the reaction to be complex. Three different types of radical‐induced decomposition are di
ISSN:0165-0513
DOI:10.1002/recl.19710900104
出版商:WILEY‐VCH Verlag
年代:1971
数据来源: WILEY
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4. |
Investigations on sterols XXXVII: New routes to 9,10‐isomers of 6‐dehydroprogesterone |
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Recueil des Travaux Chimiques des Pays‐Bas,
Volume 90,
Issue 1,
1971,
Page 27-32
M.P. Rappoldt,
T.H.R. Rix,
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摘要:
AbstractThe synthesis of 6‐dehydro‐9β, 10α‐progesterone (IV) from progesteroneviairradiation of 3,20‐bis(ethylenedioxy)pregna‐5,7‐diene (II) is described. An analogous synthesis has been accomplishedvia3‐(ethylenedioxy)pregna‐5,7‐dien‐20‐one (VI).Pyrolysis of the 9,10‐seco‐bisacetal (IX), a vitamin D analogue, followed by hydrolysis and isomerization, gave the 8α,10α‐isome
ISSN:0165-0513
DOI:10.1002/recl.19710900105
出版商:WILEY‐VCH Verlag
年代:1971
数据来源: WILEY
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5. |
The structure of dimethyl 1, 1′‐dimethylbicyclopropyl‐2,2′‐dicarboxylate |
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Recueil des Travaux Chimiques des Pays‐Bas,
Volume 90,
Issue 1,
1971,
Page 33-38
C. Jongsma,
H. van Der Meer,
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ISSN:0165-0513
DOI:10.1002/recl.19710900106
出版商:WILEY‐VCH Verlag
年代:1971
数据来源: WILEY
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6. |
Thiophene analogues of fluorene and diphenylmethane‐autoxidation reactions |
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Recueil des Travaux Chimiques des Pays‐Bas,
Volume 90,
Issue 1,
1971,
Page 39-45
G. Rawson,
Hans Wynberg,
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摘要:
AbstractOxidation of the isomeric cyclopentadithiophenes by oxygen in the presence of potassiumt‐butoxide int‐butanol‐dimethyl sulfoxide (4 : 1), or Triton B in pyridine, caused a cleavage reaction to occur and gave the corresponding bithienylcarboxylic acids. In contrast, the dithienylmethanes gave the corresponding dithienyl ketones. The Michael reaction of 7H‐cyclopenta[1,2‐b: 4,3‐b′]dithiophene with acrylonitrile is a
ISSN:0165-0513
DOI:10.1002/recl.19710900107
出版商:WILEY‐VCH Verlag
年代:1971
数据来源: WILEY
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7. |
Thiophene analogues of fluorenone: Cleavage reactions |
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Recueil des Travaux Chimiques des Pays‐Bas,
Volume 90,
Issue 1,
1971,
Page 46-55
G. Rawson,
Hans Wynberg,
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摘要:
AbstractThe cleavage reactions of non‐enolizable thienyl ketones have been studied. Potassiumt‐butoxide int‐butanol, ether or dioxane has proved to be a mild cleavage reagent. With most ketones high yields of acids were obtained after a short reaction time at room‐temperature. Possible mechanisms for these mild reactions and theHaller‐Bauercleavage of thienyl ketones are
ISSN:0165-0513
DOI:10.1002/recl.19710900108
出版商:WILEY‐VCH Verlag
年代:1971
数据来源: WILEY
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8. |
The crystal structure of MnNb4S8 |
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Recueil des Travaux Chimiques des Pays‐Bas,
Volume 90,
Issue 1,
1971,
Page 56-64
K. Anzenhofer,
J.J. de Boer,
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摘要:
AbstractUsing X‐ray reflection intensities collected with a single crystal, the crystal structure of MnNb4S8has been determined. The position of Mn is uniquely defined. The difficulties arising in space group determination and crystal structure refinement are discussed in some detail; the most essential structural features are presented and compared with those of MnNb3S
ISSN:0165-0513
DOI:10.1002/recl.19710900109
出版商:WILEY‐VCH Verlag
年代:1971
数据来源: WILEY
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9. |
Koch‐Haaf carboxylations oftert‐alkyl substituted cycloalkanols |
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Recueil des Travaux Chimiques des Pays‐Bas,
Volume 90,
Issue 1,
1971,
Page 65-80
J.A. Peters,
H. van Bekkum,
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摘要:
AbstractContrary to literature data 1‐isopropylcyclohexanol afforded both 1‐isopropylcyclohexanecarboxylic acid and 2‐cyclohexyl‐2‐methylpropanoic acid upon carboxylation by the method ofKoch.The Koch‐Haaf carboxylation of a number oftert‐alkyl substituted cycloalkane derivatives has been studied. Side reactions were suppressed by using the Haaf conditions with slow stirring of the reaction mixture.tert‐Butylcyclohexanols afforded 1‐tert‐butylcyclohexanecarboxylic acid accompanied by 2‐methyl‐2‐(1‐methylcyclohexyl)propanoic acid. In the Koch‐Haaf reaction of 3‐tert‐butylcyclopentanol and 4‐tert‐butylcycloheptanol more complex rearrangements occurred. The main products were 1,2,2‐trimethylcyclohexanecarboxylic acid and 2‐cyclohexyl‐2,3‐dimethylbutanoic acid, respectively.From the composition of the reaction products conclusions were drawn concerning the mechanisms of the rearrangements involved in these reactions. In some of the reactions protonated cyc
ISSN:0165-0513
DOI:10.1002/recl.19710900110
出版商:WILEY‐VCH Verlag
年代:1971
数据来源: WILEY
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10. |
Enthalpies of transfer of alkali halides between different solvents |
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Recueil des Travaux Chimiques des Pays‐Bas,
Volume 90,
Issue 1,
1971,
Page 81-86
G. Somsen,
L. Weeda,
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摘要:
AbstractEnthalpies of solution of alkali halides in formamide,N‐methylformamide,N, N‐dimethylformamide,N‐methylacetamide, dimethyl sulfoxide, water, methanol and ammonia are discussed. The ensuing enthalpies of transfer between any two solvents are nearly constant for salts with a common anion. The enthalpies of solution of a single salt in the different liquids can be correlated with the structure of the so
ISSN:0165-0513
DOI:10.1002/recl.19710900111
出版商:WILEY‐VCH Verlag
年代:1971
数据来源: WILEY
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