摘要:

AbstractThe synthesis of some 3‐O‐long‐chain alkyl ethers of D‐glucitol, D‐mannitol, and mixtures thereof, from readily available di‐O‐isopropylidene derivatives of D‐glucose and D‐fructose is described. Some physical characteristics including critical‐micellar‐concentration (CMC) values, Krafft temperatures, thermotropic and lyotropic liquid‐crystal beha

ISSN:0165-0513    

DOI:10.1002/recl.19951140702

出版商:WILEY‐VCH Verlag    

年代:1995

数据来源: WILEY

摘要:

AbstractA single reagent,i.e. n‐butyl nitrite, can be used to oxidize an aromatic amine, or the correspondingN‐methylene derivative, to a diazo compound followed by its subsequent reduction to hydrocarbon in a single batch. Alternatively, a chloro derivative can be obtained if carbon tetrachloride is used as the solvent. The reactions appear to be general and complete product identification was accomplis

ISSN:0165-0513    

DOI:10.1002/recl.19951140703

出版商:WILEY‐VCH Verlag    

年代:1995

数据来源: WILEY

摘要:

AbstractThe ligand 1,6‐bis(3,5‐dimethylpyrazol‐1‐yl)‐2,5‐dimethyl‐2,5‐diazahexane (debd), which has been synthesized from 3,5‐dimethylpyrazole,N,N′‐dimethylethanediamine and formaldehyde, partially disintegrates when reacted with zinc dichloride or with zinc dibromide in methanol. The resulting compounds contain the unique bis(pyrazolato)‐bridged tetrahalogenido dizinc(II) anion. The compound [Zn(debd)Cl]2[Zn2(dmpz)2Cl4], with formula C42H70Cl6N16Zn4andMr= 1273.36, is obtained from methanol as monoclinic crystals, spacegroupP21/cwitha= 15.990(2) Å,b= 16.394(2) Å,c= 12.006(1) Å, β = 100.61(1)°,V= 3093.4(5) Å3, Zm= 2,Dx= 1.37 g.cm−3, as measured at room temperature with Mo(Kα) radiation to a finalRvalue of 0.062 (wR= 0.065) for 2465 significant [I>2σ‐(I)] reflections.The asymmetric unit comprises half the formula unit. The cation consists of a Zn2+ion in a distorted trigonal bipyramidal environment of a chloride ion at 2.221(3) Å, an amine nitrogen at 2.17(1) Å and a pyrazole nitrogen at 2.05(1) Å in the equatorial plane, with an amine nitrogen at 2.27(1) and a pyrazole nitrogen at 2.14(1) Å in the axial positions. The largest distortion is in the axis of the trigonal bipyramide with an N‐Zn‐N angle of 150.2(5)°.The anion consists of two Zn2+ions, which are bridged by two deprotonatedThe authors realise that the recommended IUPAC term is (de)hydronated instead of (de)protonated to indicate loss/addition of H+.dimethylpyrazole ligands with N‐Zn distances of 1.97(1) and 1.98(1) Å, while each Zn2+ion is further bound to two chloride ions at 2.276(4) and 2.261(4) Å. The Zn

ISSN:0165-0513    

DOI:10.1002/recl.19951140704

出版商:WILEY‐VCH Verlag    

年代:1995

数据来源: WILEY

摘要:

AbstractThe term “Maillard reaction” is used to describe a complex set of reactions in foods leading to flavour generation and non‐enzymatic browning. The first step in this process is the so‐called Amadori rearrangement: a reducing saccharide and a peptide fragment react to form an Amadori Rearrangement Product (ARP). To be able to do model studies on flavour generation, gram amounts of pure ARP are required. In the present study, glucose‐derived ARPs were synthesised from specifically protected and activated starting compounds. After deprotection and purification, pure ARPs were obtained. This is the first time that ARPs of dipeptides have been

ISSN:0165-0513    

DOI:10.1002/recl.19951140705

出版商:WILEY‐VCH Verlag    

年代:1995

数据来源: WILEY

摘要:

AbstractThe preferred conformation of threeNα‐acetylated Aib/Iva host/guest pentapeptide esters and theirNα‐benzyloxycarbonylated synthetic precursors, prepared by solution methods and fully characterized, were examined in chloroform solution using FT‐IR absorption and1H‐NMR and in the crystal state by X‐ray diffraction. All these peptides are folded in a 310‐helix structure, irrespective of the experimental conditions used in the conformational analysis. In the crystal state the screw sense preference of the helical structure that is formed seems to be governed by the position of the single Iva residue in the peptide main chain, the ethyl side‐chain disposition, and the nature of theN

ISSN:0165-0513    

DOI:10.1002/recl.19951140706

出版商:WILEY‐VCH Verlag    

年代:1995

数据来源: WILEY

摘要:

AbstractA multi‐step synthesis of phosphinylphosphonate analogue 12 of the proposed farnesyl‐farnesyl‐enzyme (FFE) intermediate in the enzymatic conversion of farnesyl pyrophosphate to squalene is described. In addition, evidence is presented of the inhibitory effect of 12 on squalene syn

ISSN:0165-0513    

DOI:10.1002/recl.19951140707

出版商:WILEY‐VCH Verlag    

年代:1995

数据来源: WILEY

摘要:

Abstract[Bu4N][Ni(mdt)2] (H2mdt = 2H‐1,3‐dithiole‐4,5‐dithiol) has been prepared in a three‐step synthesis from [Bu4N]2[Zn(dmit)2] (H2dmit = 2‐thione‐1,3‐dithiole‐4,5‐dithiol). The crystal structure is reported which shows that the Ni(mdt)2anion is distorted significa

ISSN:0165-0513    

DOI:10.1002/recl.19951140708

出版商:WILEY‐VCH Verlag    

年代:1995

数据来源: WILEY

ISSN:0165-0513    

DOI:10.1002/recl.19951140709

出版商:WILEY‐VCH Verlag    

年代:1995

数据来源: WILEY

ISSN:0165-0513    

DOI:10.1002/recl.19951140711

出版商:WILEY‐VCH Verlag    

年代:1995

数据来源: WILEY

ISSN:0165-0513    

DOI:10.1002/recl.19951140701

出版商:WILEY‐VCH Verlag    

年代:1995

数据来源: WILEY