摘要:

Abstract2‐Chlorotetrahydrofuran (2‐Cl‐THF) is formed in 85% yield by reaction of sulfuryl chloride with excess THF. 2‐Cl‐THF reacts with alcohols, phenols, acids, thiols, azoles, amides and imides to give the corresponding tetrahydro‐2‐furanyl derivatives. Reaction with uracil derivatives providesN1‐ andN3‐monosubstituted andN1,N3‐disubstituted compounds. The reaction with alcohols provides a convenient general procedure for protecting the hydroxyl function. The THF group can be readily removed by acid catalyzed hydrolysis or reaction with methanol. The THF derivative of diphenylacetic acid can also be utilised for introducing the tetrahydro‐2‐furanyl moiety. THF ethers are converted into alkyl bromides by treatment with triph

ISSN:0165-0513    

DOI:10.1002/recl.19790980602

出版商:WILEY‐VCH Verlag    

年代:1979

数据来源: WILEY

摘要:

AbstractAnalysis of single resonance13C‐FT NMR spectra has yielded the vicinal13C‐1H coupling constants in monosubstituted propanes for substituents from the first row of the Periodic Table. Directly bonded13C‐1H, vicinal1H‐1H and some directly bonded13C‐13C coupling constants are also reported. The influence that the substituent electronegativity of the elements from the first row of the Periodic Table exerts on the vicinal13C‐1H coupling constant is discussed qualitatively in terms of molecular orbital theory. The effects of substituents from the first row are compared with the effects of halogen s

ISSN:0165-0513    

DOI:10.1002/recl.19790980603

出版商:WILEY‐VCH Verlag    

年代:1979

数据来源: WILEY

摘要:

AbstractEnergies are calculated for the cations obtained by protonation of butatriene and 1,2,3‐pentatriene at various positions. The relative stabilities of the various ions are discussed. The ion of lowest energy is an allylic cation obtained by rotation around a CC bond after or concomitant with protonation. Experimentally, instead of this ion the next higher in energy is formed. The latter is a propargylic ion, formed by proton attack at the terminal carbon atom. Apparently, rotation is not appreciable in the transition state of the experimental protonat

ISSN:0165-0513    

DOI:10.1002/recl.19790980604

出版商:WILEY‐VCH Verlag    

年代:1979

数据来源: WILEY

摘要:

AbstractSolubility measurements of calcium(II) sulfate in aqueous solutions of (hydroxy)carboxylates and alditols have yielded apparent stability constants (M−1, at 25° and 0.2–0.8M) for the complexes of calcium(II) with d‐gluconate (23), d‐lactate (17), acetate (7), and various alditols

ISSN:0165-0513    

DOI:10.1002/recl.19790980605

出版商:WILEY‐VCH Verlag    

年代:1979

数据来源: WILEY

摘要:

AbstractThe coding system proposed in the previous paper is extended to reactions involving an odd number of atoms, one of which is coordinatively unsaturated. This atom can extend its bonding with two units. Chelotropic reactions fit into this class characterized by operators (+ ‐)n+. Reactions in the reversed direction (operator (‐ +)n‐) are equally important. The coding system allows the design of new reac

ISSN:0165-0513    

DOI:10.1002/recl.19790980606

出版商:WILEY‐VCH Verlag    

年代:1979

数据来源: WILEY

摘要:

AbstractRate constants for addition of hydroxylamine to a series of twenty‐four ketones have been measured, in water at 25,00 ± 0,02°C, for both acid‐catalyzed (k H +) and pH‐independent (ko) pathways. Structural effects seem to be operating in the same manner on koand k H +values, except in a few cases. Results are consistent with a “reactant‐lik

ISSN:0165-0513    

DOI:10.1002/recl.19790980607

出版商:WILEY‐VCH Verlag    

年代:1979

数据来源: WILEY

摘要:

AbstractA number of compounds of general formula M(PPO)nX2are described, the metal ion being Zn(II), Cd(II) and Hg(II) and the anions Cl−, Br−, I−, NO3−, ClO4−and NCS−; PPO stands for 2,5‐diphenyloxazole andn= 1, 2, 4.The complexes are prepared by reaction of the corresponding metal salts with the molten ligand in the required stoicheiometrical ratio and are characterized by chemical analyses and physical measurements.Their stereochemistry has been assigned on the basis of IR, far IR spectroscopy and molar conductivity values. The ligand PPO is shown to co‐ordinate with metal ionsviathe lone‐pair electrons of the nitrogen atom. All the complexes have generally a distorted tetrahedra

ISSN:0165-0513    

DOI:10.1002/recl.19790980608

出版商:WILEY‐VCH Verlag    

年代:1979

数据来源: WILEY

摘要:

AbstractThe construction of an automatic adiabatic calorimeter is described. A block diagram is given of the data‐logging system used.n‐Heptane is used to check the performance of the appara

ISSN:0165-0513    

DOI:10.1002/recl.19790980609

出版商:WILEY‐VCH Verlag    

年代:1979

数据来源: WILEY

摘要:

AbstractThe preparation and properties of the compounds CuXR4tms (X = Cl, Br, I: R = Me and R2= Pm; X = SCN: R = Me) are reported. The compound CuI(Pm2tms) from which the crystal structure has been solved crystallizes in the triclinic space groupPl [a= 11.822(3),b= 10.572(3),c= 7.833(3) Å, α = 95.62(3), β = 111.73(3), γ = 68.20(2)°] and contains two formula units per unit cell. The structure was refined to a conventionalRvalue of 0.056 for 3829 independent non‐zero reflections. It consists of dimeric molecules in which copper is approximately tetrahedrally coordinated. The two copper atoms are bridged by one of the sulfur atoms of each thiuram monos

ISSN:0165-0513    

DOI:10.1002/recl.19790980610

出版商:WILEY‐VCH Verlag    

年代:1979

数据来源: WILEY

摘要:

AbstractThe preparation of an arsenic(III) dithiocarbamato iodo compound, MeAs(Me2dtc)I, and of its iodine complex, MeAs(Me2dtc)I2, is reported. The crystal structure of the iodine complex was determined by an X‐ray analysis. The monoclinic cell, space groupP21/c, witha= 12.838(3),b= 8.374(1),c= 22.944(2) Å and β = 105.44(1)°, contains eight formula units. The two symmetry independent units are arranged in a nearly perfect C‐centred lattice. The phase problem was solved by the DIRDIF procedure (direct methods, including origin fixation, applied to difference structure factors). The atomic parameters were refined to a conventionalRvalue of 0.07.The structure consists of I2IAsII2IAs chains, cross‐linked by IAsIAs chains to form two‐dimensional networks. The arsenic atoms are in quadrilaterally pyramidal coordination: As is slightly above the S,S,I,I‐plane; the methyl carbon forms the top of the pyramid. This methyl group breaks through the

ISSN:0165-0513    

DOI:10.1002/recl.19790980611

出版商:WILEY‐VCH Verlag    

年代:1979

数据来源: WILEY