摘要:

AbstractPyridopyrimidine reacted with aromatic aldehydes afforded the arylhydrazone2a,bwhich could be cyclized into the pyrido[2,3‐d][1,2,4]triazolo[4,3‐a]pyrimidine3a,b, with formic acid, and carbon disulphide to give pyrido[2,3‐d][1,2,4]traizolo[4,3‐a]pyrimidine4, 5.Reaction of1with nitrous acid afforded tetrazolo[1,5‐a]pyrido[2,3‐d]pyrimidine6, which was reduced by zinc dust to give 2‐amino‐pyrido‐[2,3‐d]pyrimidine7.Finally the reaction of 2‐hydrazino1with D‐xylose or D‐glucose afforded the acyclic N‐nucleoside8, 11which were converted into tetra/pentaO‐acetate acyclicC‐nucleoside9, 12in acetic anhydride/pyridine. De‐acetylation of compound

ISSN:0009-4536    

DOI:10.1002/jccs.200800031

出版商:WILEY‐VCH Verlag    

年代:2008

数据来源: WILEY

摘要:

AbstractEnamination of a wide variety of primary amines was successfully described with excellent chemo‐selectivity in the presence of catalytic amounts of β‐cyclodextrin in water under mild conditions. Aliphatic amines also reacted efficiently to produce the corresponding enamin

ISSN:0009-4536    

DOI:10.1002/jccs.200800032

出版商:WILEY‐VCH Verlag    

年代:2008

数据来源: WILEY

摘要:

AbstractTwo new phenol glycosides, 3,4,5‐trimethoxyphenol‐1‐O‐β‐d‐glucopyranosyl‐4′,6′‐O‐(E)‐diferuloyl ester (1), 3,5‐dimethoxy‐4‐hydroxyphenylmethanol‐4‐O‐β‐d‐glucopyranosyl‐4′,6′‐O‐(E)‐diferuloyl ester (2), together with six known compounds were isolated from then‐butanol extract ofRhus javanicavar.roxburghianaand their structur

ISSN:0009-4536    

DOI:10.1002/jccs.200800033

出版商:WILEY‐VCH Verlag    

年代:2008

数据来源: WILEY

摘要:

AbstractTriethylammonium fluorochromate(VI), (C2H5)3NHCrO3F, TriEAFC and triethylammonium chlorochromate(VI), (C2H5)3NHCrO3Cl, TriEACC were prepared, supported on silica gel and used to quantitatively oxidize a number of organic substrates. These supported triethylammonium halochromates are versatile reagents ensuring effective oxidation of organic compounds, in particular of alcohols, under mild conditions. The durability, ease of work up and efficiency of TriEAFC and TriEACC are considerably increased upon their absorption on silica gel.

ISSN:0009-4536    

DOI:10.1002/jccs.200800034

出版商:WILEY‐VCH Verlag    

年代:2008

数据来源: WILEY

摘要:

AbstractOxidation of 3‐furfurylcarbinols3a‐eand7with bromine in acetone‐water solution gave the 2‐substituted‐3‐furfurals4a‐eand8in good yields, respectively. Reaction of 2‐alkyl‐3‐furfurylcarbinols9aand9bwith bromine in acetone‐water gave the bromoalkyl 3‐furfuryl ketones10aand10bas the major products. A reaction mechanismviathecis‐transisomerization of the 2‐ene‐1,4‐diones13and14was proposed to account for the transposition of the alkyl group of the 3‐furfurylcarbinols3, 7and9to the 2‐position on the

ISSN:0009-4536    

DOI:10.1002/jccs.200800035

出版商:WILEY‐VCH Verlag    

年代:2008

数据来源: WILEY

摘要:

AbstractThe ethylenebis(N‐methylimidazolium) chlorochromate was prepared by addition ofN‐methylimidazole to 1,2‐dibromoethane to form the corresponding dibromide salt and subsequent treatment of this salt with CrO3in 6N HCl solution. It is a stable yellow‐orange solid which selectively oxidized benzylic and allylic alcohols, hydroquinones and trimethylsilyl ethers in refluxing acetonitrile. Oxidation of alcohols was also examined under solvent‐free conditions and showed much better yields of the corresponding carbonyls in a very short reaction time when compared with the convention

ISSN:0009-4536    

DOI:10.1002/jccs.200800036

出版商:WILEY‐VCH Verlag    

年代:2008

数据来源: WILEY