ISSN:0165-0513    

DOI:10.1002/recl.19831021001

出版商:WILEY‐VCH Verlag    

年代:1983

数据来源: WILEY

摘要:

AbstractActivation of RuCl3‐impregnated silica by hydrogen treatment at high temperature, up to 700°C, is superior to a procedure involving air calcination of the material prior to reduction. Upon direct reduction, sintering hardly occurs, whereas the Ru metal surface, as measured by hydrogen desorption, increases at higher activation temperature, due to the removal of chlorine impurities from the Ru surface. Activity measurements of the Ru catalysts for the liquid‐phase hydrogenation of benzene and cyclohexene reflect the favourable effect of the high‐temperature reduction of RuCl3/SiO2. Similar phenomena are observed for some PdRu/SiO2cat

ISSN:0165-0513    

DOI:10.1002/recl.19831021002

出版商:WILEY‐VCH Verlag    

年代:1983

数据来源: WILEY

摘要:

AbstractThe synthesis of 7β‐amino‐1,3,5(10)‐estratriene‐3,17β‐diol (1) has been accomplished using a sequence of transformations proceeding through the 6α,7α‐epoxy‐1,3,5(10)‐estratriene‐3.17β‐diol dibenzyl ether (6). This latter compound is reduced by LiAlH4to give the 7α‐hydroxy compound 7, which, upon subsequent treatment with tosyl chloride (to give8), followed by reaction with NaN3, provided the 7β‐azido‐1,3,5(10)‐estratriene‐3,17β‐diol dibenzyl ether (9). Reduction of9with LiAlH4, followed by catalytic removal of the benzyl ethers, gave1.Attempts to obtain an epoxide from 1,3,5(10),6‐estratetraene‐2,3–17β‐triol tribenzyl ether (17) failed, and led to the isolation of the corresponding 6α,7α‐diol (19) and 6β,7α‐diol (20). A novel transformation,viz.subsequent treatment of either19or20with SOCl2and LiAlH4, selectively provided 1,3,5(10)‐estratriene‐2,3,7α,17β‐tetraol 2,3,17‐tribenzyl ether (21). Further treatment of21, as delineated for7, prov

ISSN:0165-0513    

DOI:10.1002/recl.19831021003

出版商:WILEY‐VCH Verlag    

年代:1983

数据来源: WILEY

摘要:

AbstractThe preparation of two diphosphorylated Lipid A analogues, which contain α‐ or β‐phosphates at the reducing end, is described (i.e.compounds14dand15d, respectively). The synthesis of these compounds was accomplished using:(i)two suitably protected glucosamine derivatives,i.e.the non‐reducing part6and the reducing part3;(ii)an iridium catalyst to isomerize the anomeric allyl ethers quantitatively into 1‐propenyl ethers, which can then be removed to give simultaneously oxazoline functions (i.e.isomerization of4binto5and of7ainto7b);(iii)the levulinoyl* group for temporary protection of the 4‐hydroxyl group;(iv)1‐hydroxybenzotriazole‐activated phosphorylating agents for the phosphorylation of the 4′‐hydroxyl group (i.e.phosphorylation of compound8to give10a,b);(v)2,2,2‐tribromoethyl phosphate for the phosphorylation of the reducing anomeric centre of Lipid A analogues (i.e.phosphorylation of11a,bto afford13a,b).Non‐reducing part6and reducing part3were reacted together to give the disaccharide7a, which was converted into non‐phosphorylated Lipid A precursor8. Phosphorylation of compound8at its4′‐hydroxyl function and at its reducing anomeric centre resulted in the formation of fully protected α‐phosphorylated Lipid A analogues14aand14btogether with the fully protected β‐phosphorylated analogues15aand15b. Final removal of all the protecting groups from14a,band15a,bgave the α‐phosphorylated Lipid A analogue14dand the β‐phospho

ISSN:0165-0513    

DOI:10.1002/recl.19831021004

出版商:WILEY‐VCH Verlag    

年代:1983

数据来源: WILEY

摘要:

AbstractThe synthesis, purification and analysis of three tritiated neuropeptides are described. Org 2766 (an ACTH (4‐9) analogue) and Org GK 78 (des‐Tyr‐γ‐endorphin) were labelled in the aromatic ring of phenylalanine by catalytic deiodination of the (p‐iodophenyl)alanine precursors using3H2.Org 5878 (des‐enkephalin‐γ‐endorphin) was labelled in the lysine residue by reduction of the L‐2,6‐diamino‐4‐hexynoic acid‐containing analogue with3H2. The peptides were purified by preparative HPLC using ammonium acetate buffer systems. The chemical purity was determined by1H NMR, the radiochemical purity was measured by HPLC and the3H distribution by3H NMR. Specific activities (as determined by HPLC) wereca.900 GBq mmol−1for Org 2766 and Org GK 78 an

ISSN:0165-0513    

DOI:10.1002/recl.19831021005

出版商:WILEY‐VCH Verlag    

年代:1983

数据来源: WILEY

摘要:

AbstractOn reacting 3‐deoxy‐3‐hydrazino‐1,2: 5,6‐di‐O‐isopropylidene‐α‐D‐allofuranose (2) or 3‐deoxy‐3‐hydrazino‐1,2: 5,6‐di‐O‐isopropylidene‐α‐D‐glucofuranose (8) withN‐methylpyrimidinium methyl sulfate (4) at room temperature, formation of 3‐deoxy‐3‐N‐pyrazolyl‐1,2: 5,6‐di‐O‐isopropylidene‐α‐D‐allofuranose (3) and 3‐deoxy‐3‐N‐pyrazolyl‐1,2: 5,6‐di‐O‐isopropylidene‐α‐D‐glucofuranose (9), respectively, takes place. This ring transformation has been explained by an ANRORC mechanism. Similarly, 6‐deoxy‐6‐hydrazino‐1,2‐O‐isopropylidene‐α‐D‐glucofuranose (10) and methyl‐4,6‐O‐benzylidene‐2‐deoxy‐2‐hydrazino‐α‐D‐mannopyranoside (11) react with the pyrimidinium salt to give the corresponding pyrazolylaldoses.Starting from 3,6‐anhydro‐5‐deoxy‐5‐hydrazino‐1,2‐O‐isopropylidene‐β‐L‐idofuranose (16), in addition to the expected 3,6‐anhydro‐5‐deoxy‐5‐N‐pyrazolyl‐1,2‐O‐isopropylidene‐β‐L‐idofuranose (17a), 3,6‐anhydro‐5‐deoxy‐5‐(1,2,4‐triazol‐1‐yl)‐1,2‐O‐isopropylidene‐β‐L‐idofuranose (17b) is formed. The same conversion of substituted hydrazines into pyrazolyl and triazolyl derivatives is observed in the reaction of 1‐deoxy‐1‐hydrazino‐2,3‐O‐isopopylidene‐D‐ribofuranose (12) with the pyrimidinium salt. This pyrimi

ISSN:0165-0513    

DOI:10.1002/recl.19831021006

出版商:WILEY‐VCH Verlag    

年代:1983

数据来源: WILEY

摘要:

AbstractEleven deuterated analogues of mianserin have been synthesized and analyzed by1H and13C NMR. Based on these compounds, the aromatic part of the1H spectrum of mianserin could be interpreted.

ISSN:0165-0513    

DOI:10.1002/recl.19831021007

出版商:WILEY‐VCH Verlag    

年代:1983

数据来源: WILEY

摘要:

AbstractThe asymmetric phase‐transfer‐catalysedDarzenscondensation of aldehydes and ketones with the chiral reagent L‐menthyl chloromethanesulphonate, using triethylbenzylammonium chloride (TEBA) as the phase‐transfer catalyst to give α,β‐epoxysulphonate esters (oxiranesulphonate esters) in 9–17% chiral induction, is described. The stereochemical course of the chiral induction

ISSN:0165-0513    

DOI:10.1002/recl.19831021008

出版商:WILEY‐VCH Verlag    

年代:1983

数据来源: WILEY

摘要:

AbstractReaction of the anion derived from phosphine oxide4with saturated and unsaturated aldehydes provides diastereomeric mixtures of the adducts5. After removal of the protecting group these can be separated and, upon reaction with base, afford the pureE‐and Z‐isomers of glyceryl enol ethers7in good yie

ISSN:0165-0513    

DOI:10.1002/recl.19831021009

出版商:WILEY‐VCH Verlag    

年代:1983

数据来源: WILEY

ISSN:0165-0513    

DOI:10.1002/recl.19831021010

出版商:WILEY‐VCH Verlag    

年代:1983

数据来源: WILEY