摘要:

AbstractThe strong preference of the SO bond in trimethylene sulfite for an axial position (chair conformation), may not always prevent the molecules from occurring also in other conformations. A highly polar form having an equatorial SO bond may show up in polar solvents, due to a favourable interaction energy, and supported bye.g.ana→echange of atert.‐butyl group.Closer examination of the electric moment of the sulfite group suggests that the lone‐pair of electrons on the sulfur contributes significantly to the overall moment. This interpretation provides a consistent description in terms of additive partial moments for the dipole moments of cyclic sulfites, thionyl chloride and related

ISSN:0165-0513    

DOI:10.1002/recl.19670860402

出版商:WILEY‐VCH Verlag    

年代:1967

数据来源: WILEY

摘要:

Abstract2‐Oxo‐2‐phenoxy‐1, 3, 2‐dioxaphosphorinane (propane‐1, 3‐phenylphosphate) crystallizes in the orthorhombic system, space group Pna21, Z = 4. The unit cell dimensions are a = 15.55, b = 11.06, c = 5.97 Å. The structure was solved by the heavy atom technique and refined by the method of least squares using eye‐estimated three‐dimensional data obtained with copper radiation at room temperature. The dioxaphosphorinane ring has the chair conformation with the double‐bonded oxygen in equatorial and the phenoxy gro

ISSN:0165-0513    

DOI:10.1002/recl.19670860403

出版商:WILEY‐VCH Verlag    

年代:1967

数据来源: WILEY

摘要:

AbstractThe kinetic isotope effect of hydrogen in the nitration of anthracene with nitronium tetrafluoroborate has been determined, using anthracene‐9‐d as substrate. In sulfolane as solvent at 30° and in acetonitrile at 0°,kH/kDwas found to be equal to 2.6 ± 0.3 and 6.1 ± 0.6, respectively. The kinetic isotope effect of hydrogen in the nitration of naphthalene in these two solvents under similar reaction conditions, using naphthalene‐1,4‐d2as substrate, were found to be 1.15 ± 0.05 and 1.08 ± 0.05, respectively.UV spectral evidence was obtained that the nitration of anthracene with nitronium tetrafluoroborate in sulfolane as solvent proceedsviaan intermediate which is suggested to be the 9‐nitro‐9‐anthracenonium ion. This intermediate is formed directly on mixing the reagents. The proton transfer from this intermediate with formation of 9‐nitroanthracene is a re

ISSN:0165-0513    

DOI:10.1002/recl.19670860404

出版商:WILEY‐VCH Verlag    

年代:1967

数据来源: WILEY

ISSN:0165-0513    

DOI:10.1002/recl.19670860405

出版商:WILEY‐VCH Verlag    

年代:1967

数据来源: WILEY

摘要:

AbstractThe reaction of histidine and some other imidazole derivatives with iodine at pH8 and 50° has been followed to completion (uptake 8 moles I2per mole histidine). Products of the I2‐degradation of histidine are: carbonate, iodoform, oxalic acid, ammonia and iodide. The origin of the reaction products has been traced by using radioactively labelled compounds. An overall equation for the reaction is deduced and a tentative scheme for a reaction path is present

ISSN:0165-0513    

DOI:10.1002/recl.19670860406

出版商:WILEY‐VCH Verlag    

年代:1967

数据来源: WILEY

摘要:

AbstractMetallation of allenyl thioethers, R1CHCCHSC2H5(I) (R1= alkyl), by means of methyl‐ or butyl‐lithium in ether, followed by addition of aldehydes or ketones, R2R3C  O (R2and R3are H or alkyl), affords a mixture of the two carbinols R1CHCC[CR2R3C(OH)](SC2H5) (III) and R1CH[CR2R3(OH)] CCSC2H5(IV). By treatment of the mixture with an excess of potassium amide in liquid ammonia IV is converted into the metallated β‐hydroxy‐alkyne R1CH[CR2R3(OH)]CCH (VI), probablyviaa nucleophilic substitution at sulfur. In the cases where R1 CH3, ethanethiol is eliminated from III with formation of the metallated enynyl alcohol HCCCHCH[CR2R3(OH)], (V). A number of alkylated derivatives RCCCHR1CH2OH have be

ISSN:0165-0513    

DOI:10.1002/recl.19670860407

出版商:WILEY‐VCH Verlag    

年代:1967

数据来源: WILEY

摘要:

AbstractA series of fourO‐alkyl hydrogen methylphosphonothioates, (RO)MeP(S)OH, was resolved using both (+)‐ and (−)‐α‐phenylethylamine. Because it gives better results, is rapid and of general applicability the method is to be preferred to that in which alkaloids are used as resolving bases. In one case optical purities of the isolated enantiomers were determined after conversion into acetylcholinesterase

ISSN:0165-0513    

DOI:10.1002/recl.19670860408

出版商:WILEY‐VCH Verlag    

年代:1967

数据来源: WILEY

摘要:

AbstractThe sulfite concentrations in aqueous solutions of methoxybenzenediazosulfonates of pH = 7.8 were determined by dead‐stop end‐point titrations at 25°.ortho‐Methoxybenzenediazosulfonate dissociates slowly after being dissolved in water.Dissociation and rate constants derived areK= 2.4 × 10−10mole l−1=ka/kb, withka= 9.0 × 10−8s−1andkb= 375 1 mole−1s−1.para‐Methoxybenzenediazosulfonate is immediately at its equilibrium dissociation in solution withK= 6.6 × 10−10mole l−1,ka= 1.5 ×

ISSN:0165-0513    

DOI:10.1002/recl.19670860409

出版商:WILEY‐VCH Verlag    

年代:1967

数据来源: WILEY

摘要:

AbstractPeak broadening in paper chromatography has been investigated as a function of the flow‐rate of the eluent.The contribution of longitudinal diffusion and the combined contributions of resistance to mass‐transfer and eddy diffusion to peak broadening have been calculated separately.The last‐mentioned effects are responsible for more than 50% of the peak broadening at the flow‐rate which is obtained in practice, and for medium Rfvalues.It appeared, once more, that longitudinal diffusion occurs both in the mobile and in the stationar

ISSN:0165-0513    

DOI:10.1002/recl.19670860410

出版商:WILEY‐VCH Verlag    

年代:1967

数据来源: WILEY

ISSN:0165-0513    

DOI:10.1002/recl.19670860411

出版商:WILEY‐VCH Verlag    

年代:1967

数据来源: WILEY