ISSN:1057-5634    

DOI:10.1080/10575639208048876

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor

摘要:

A general route is described for the synthesis of 8-arylamino derivatives of 2′-deoxyguanosine. the method takes advantage of (a) the far greater stability of the ribonucleoside series to acid conditions during the introduction of the aminoaryl group and (b) a modified form of Barton's radical deoxygenation procedure to remove the 2′-hydroxyl group. the synthetic pathway allows the preparation of the desired materials on a gram scale and avoids the use of an ultimate carcinogen as an intermediate.

ISSN:1057-5634    

DOI:10.1080/10575639208048877

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor

摘要:

From cultures ofAzotobacter vinelandiiDSM 87 (ATCC 12837) an azotobactin was isolated and its structure was elucidated by MS, NMR, and chemical degradation studies. This is the second representative of its class of bacterial siderophores so far encountered. of special interest also in respect of the relatedPseudomonassiderophores (pyoverdins) is a novel hydroxamic acid unit (N5-hydroxy-N5-hydroxybutyryl-ornithine) as one of the binding sites for Fe3+.

ISSN:1057-5634    

DOI:10.1080/10575639208048878

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor

摘要:

Closure of the six-membered C ring of pentacyclic mavacurine type alkaloids, by formation of either C6-C7or N4-C5bonds, failed. In contrast, 6a-homopleiocarpamine has been synthesized using as the key step an electrophilic cyclization upon the indole 3-position (bond formed C6a-C7) from an appropriately substituted tetracyclic derivative having a three-carbon chain on the piperidine nitrogen.

ISSN:1057-5634    

DOI:10.1080/10575639208048879

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor

摘要:

The title amino acids, (2S,3R)-3-amino-2-hydroxy-5-methyl-hexanoic acid (AHMHA) and (2S,3R)-3-amino-2-hydroxy-4-phenylbutanoic acid (AHPBA), are stereoselectively prepared from (4R,5R)-5-allyl-4-methoxy-2-oxazolidinone which is readily accessible from the previously reported chiral synthon, (4R,5R)-5-phenylseleno-4-methoxy-2-oxazolidinone.

ISSN:1057-5634    

DOI:10.1080/10575639208048880

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor

摘要:

A two-step regioselectiveO-methylation of hydroxyl groupsvia1,3-benzodithiol ether intermediates has been developed. theO-alkylation of alcohols containing a phenolic hydroxyl group or pyridine skeleton was successfully performed.

ISSN:1057-5634    

DOI:10.1080/10575639208048881

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor

摘要:

A new herbicidal lanostane lactone (1) has been isolated fromSporormiella australis.

ISSN:1057-5634    

DOI:10.1080/10575639208048882

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor

摘要:

Inhibitors, reaction intermediates and substrate analogs of neuramic acid were studied by molecular graphics. Based on this chemically modified analogs of siastatin B, an inhibitor of neuraminidases were synthesized. the results indicated that potent inhibitors must be good topographical analogs of the oxocarbenium ion of neuraminic acid, an intermediate in the reaction catalyzed by neuraminidase.

ISSN:1057-5634    

DOI:10.1080/10575639208048883

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor

摘要:

Rationally designed analogs of siastatin B able to mimic oxocarbenium ion of neuraminic acid, an intermediate in the reaction catalyzed by the enzyme, were synthesized. Those types represented the improvement over siastatin B.

ISSN:1057-5634    

DOI:10.1080/10575639208048884

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor

摘要:

Two novel chiral porphyrins (5) and (7), with two and four alditolyl chains attached at the bridging methine carbons, have been synthesized via, respectively, coupling of the dipyrryl unit (3) with p-fluorobenzaldehyde (4) and BF3-catalyzed condensation between pyrrole and 2,3-O-isopropylidene-D-glyceraldehyde (6).

ISSN:1057-5634    

DOI:10.1080/10575639208048885

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor