摘要:

AbstractPrevious publication showed that the stereochemistry of lithium aluminum hydride reduction of cyclic ketones can be evaluated by the use of an empirical equation, . This paper reports further test of this relationship in the new system of 2,2‐dimethyl‐4‐t‐butyl‐cyclohexanone.Lithium aluminum hydride reduction of this ketone yields 95.6%trans‐alcohol (lit., 95.9%) corresponding to D̊(D̊G*)Hof 1.67Kcal/mol. With methyllithium, the ketone formed 77.5% oftrans‐alcohol (D̊(D̊G*)D̊fs= 0.67Kcal/mol). These data give a calculatedD̊G* = 0.74Kcal/molwhich agrees well with the literature value of 0.87 or 0.28Kcal/mol.Structural assignments of 2,2‐dimethyl‐4‐t‐butylyclohexanone, 1,2,2‐trimethyl‐cis‐ andtrans‐4‐t‐butylcyclohexanols by

ISSN:0009-4536    

DOI:10.1002/jccs.198300001

出版商:WILEY‐VCH Verlag    

年代:1983

数据来源: WILEY

摘要:

AbstractTwo predicative theories for superheating limits of a boiling liquid are considered in this work. In the nucleation picture, classical homogeneous nucleation theory is used to calculate superheating temperature at various pressures. In spinodal decomposition picture, stability limits are taken as the superheating temperature. A perturbed‐hard chain equation of state was developed and used for the purpose of calculating mechanical stability limit. Calculations are done for the case of normal hexane at different pressures and compared with experimental results. Classical nucleation theory gives good prediction at negative and smaller pressures. While near critical pressure, spinodal picture seems to be more accurat

ISSN:0009-4536    

DOI:10.1002/jccs.198300002

出版商:WILEY‐VCH Verlag    

年代:1983

数据来源: WILEY

摘要:

AbstractSome halo or mercaptide bridged palladium (II) dimers, [Pd(S2CNR2)X]3(R=ibutyl, X=Cl, Br, I, S‐ethyl and S‐t‐butyl) were studied by variable temperature1H nmr spectroscopy. Line shape changes of the chloro and bromo bridged dimers were interpretated by the solvolytic breaking of the Pd‐X bond, while mercaptide bridged complexes were explained in terms of slow N‐C single bond rotation. The results consist with the strengthness of the classbmetal ion with various soft dono

ISSN:0009-4536    

DOI:10.1002/jccs.198300003

出版商:WILEY‐VCH Verlag    

年代:1983

数据来源: WILEY

摘要:

AbstractThe authoret al. has recently developed as‐pseparation model CNDO‐MO method. Naphthalene, anthracene and their derivatives including CI and CH3substituted functional groups have been selected for the MO calculation. The computational results of both the ionization potentials and the dipole moments are compatible with current experimental values. We here introduce a concept of the HOMO repulsive bond order (Pp(HOMO)µv). Then it is calculated in addition to repulsive bond order (Ppµv) developed previously in this work. The result shows that both HOMO eigenvalues and thePp(HOMO)µvare the useful and powerful quantities for the predictions of reactivity and positional selectivity of the Diets Alder re

ISSN:0009-4536    

DOI:10.1002/jccs.198300004

出版商:WILEY‐VCH Verlag    

年代:1983

数据来源: WILEY

摘要:

AbstractA convenient method to prepare 4‐formyl‐3‐arylsydone (I) from 3‐arylsydnone by the Vilsmeier reaction in moderate yields (30%‐76%) was carefully investigated.According to the Schmidt reaction, I reacts with sodium azide in concentrated sulfuric acid to produce 3‐arylsydnone‐4‐carboxamide (II). But 3‐arylsydnone‐4‐carhonitrile (III) is obtained, if dilute sulfuric acid was used instead.When III treates with concentrated sulfuric acid, II is obtained in good yield. The all possible reaction mec

ISSN:0009-4536    

DOI:10.1002/jccs.198300005

出版商:WILEY‐VCH Verlag    

年代:1983

数据来源: WILEY

摘要:

AbstractThe lead complex ofN‐(3‐Aminopropyl)‐Diethanolamine (APDEA) was investigated polarographically over thepH range 10.40‐12‐85 and ligand concentration 0.0227‐1.002M. A quasi‐reversible and diffusion‐controlled reduction wave was obtained atpH≥10.40. The electron‐transfer coefficient and rate constants were determined as 0.11‐0.34 and 10

ISSN:0009-4536    

DOI:10.1002/jccs.198300006

出版商:WILEY‐VCH Verlag    

年代:1983

数据来源: WILEY

摘要:

AbstractIn the presence of a relatively small amount of bromate, maleic acid in aqueous sulfuric acid isomerizes catalytically to fumaric acid in the dark at room temperature. The concomitant presence of a suitable amount of bromine in CCI, phase raises the rate and yield significantly. The yield and rate of isomerization depend on the relative amounts of maleic acid, bromate, bromine, and sulfuric acid. For a favorable condition, nearly 90% yield can be obtained. Raising the temperature accelerates the production of fumaric acid while decreases the final yield. The isomerization reaction competes favorably with the redox reaction at room temperature while the latter dominates at high temperature. For the heterogeneous case, the agitation of the reaction mixture delays the isomerization. The presence of cumene or benzene inhibits the isomerization. Hypobromous acid is proposed to play a major role in catalyzing the isomerization. A mechanism is proposed to rationalize the experimental results.

ISSN:0009-4536    

DOI:10.1002/jccs.198300007

出版商:WILEY‐VCH Verlag    

年代:1983

数据来源: WILEY

摘要:

AbstractA homogeneous catalyst, 3‐benzyl‐5‐(2‐hydroxyethyl)‐4‐methyl‐1,3‐thiazolium chloride, for addition of aldehydes to activated double bond, was attached to 20% cross‐linked polystyrene‐divinylbenzene copolymer. The attached catalysts could be easily removed from the reaction mixture. Polymer‐attached thiazolium salts in the presence of triethylamine are active catalysts for addition of aromatic and aliphatic aldehydes toα,β‐unsaturated ket

ISSN:0009-4536    

DOI:10.1002/jccs.198300008

出版商:WILEY‐VCH Verlag    

年代:1983

数据来源: WILEY

摘要:

AbstractThe essential oils from the leaves and stems ofLitsea kostermaninChang andLitsea cubeba(lour.) Persoon, and the leaves ofLitsea gerciaeVidal were analysed to determine the detailed composition of each oils. The major constituents were isolated and identified by GLC, IR, and NMR. The analyses showed that large chemical differences exist amongL. kostermaninChang,L. gerciaeVidal andL. cubeba(lour.) Persoon.

ISSN:0009-4536    

DOI:10.1002/jccs.198300009

出版商:WILEY‐VCH Verlag    

年代:1983

数据来源: WILEY

摘要:

AbstractFrom the hexane extractive of the nutmeg ofMyristica fragransHoutt, glyceryl trimyristate (1), myristicin (11), methyleugenol (12), elemicin (13), dehydrodiisoeugenol (9), 1‐(3,4,5‐trimethoxyphenyl)‐2‐(4‐allyl‐2,6‐dimethoxyphenoxy)‐propan‐1‐ol (4), 1‐(3,4‐methylenedioxyphenyl)‐2‐(4‐allyl‐2,6‐dimethoxyphenoxy)‐propan‐1‐ol (6), and a new compound 1‐(3,4‐dimethoxyphenyl)‐2‐(4‐allyl‐2,6‐dimethoxyphenoxy) propan‐1‐ol (14) were isolated. The structure of compound (14) was determin

ISSN:0009-4536    

DOI:10.1002/jccs.198300010

出版商:WILEY‐VCH Verlag    

年代:1983

数据来源: WILEY