摘要:

AbstractIn einer vorangehenden Arbeit [2] wurde gezeigt, dass sich das triplettangeregte α, β‐ungesättigte δ‐Diketon1in die beiden stereoisomeren Cyclopropyl‐diketone2und3umlagert. Neue Resultate vermitteln nun einen näheren Einblick in die mechanistischen Aspekte dieser Photoreaktion. Die Bestrahlung der 4α‐Trideuteromethyl‐Verbindung7in Dioxan mit 2537 Å lieferte nach einem Umsatz von ≧ 30% die an C‐4 sterisch äquilibrierten Photoisomerenpaare8a, bund9a, bwährend im regenerierten Ausgangsmaterial (7) die C(4)‐Chiralität erhalten blieb.Dieser Befund spricht gegen eine konzertierte Umlagerung und ist indikativ für einen sch

ISSN:0018-019X    

DOI:10.1002/hlca.19700530402

出版商:WILEY‐VCH Verlag GmbH    

年代:1970

数据来源: WILEY

摘要:

AbstractA correlation of the photoelectron spectra oftrans‐2‐butene,trans‐acetaldehydemethylimin andtrans‐azomethane shows that the split Δ = ε (ag(n))−ε (bu(n)) between the lone pair orbitalsag(n) andbu(n) oftrans‐azomethane amounts to3.3±0.2eV. Molecular orbital calculations by the MINDO/1 procedure indicate thatag(n) lies abovebu(n). In agreement with the experimental results the π‐orbitalau(π) is predicted to fall into the interval be

ISSN:0018-019X    

DOI:10.1002/hlca.19700530403

出版商:WILEY‐VCH Verlag GmbH    

年代:1970

数据来源: WILEY

摘要:

AbstractFrom cultures of aPhomaspecies (strain S 298) (Fungi imperfecti) two new antibiotics, phomine (1) and 5‐dehydrophomine (4) have been isolated. Phomine and 5‐dehydrophomine represent a novel type of macrolide antibiotics, the large lactone ring being fused to a highly substituted octahydro‐isoindole system. Both show cytostatic act

ISSN:0018-019X    

DOI:10.1002/hlca.19700530404

出版商:WILEY‐VCH Verlag GmbH    

年代:1970

数据来源: WILEY

摘要:

AbstractA prebullvalene lactone exhibits fluxional isomerism in solution. Analysis of proton NMR. spectra at 100 MHz and 220 MHz together with variable temperature studies show that the species existing in solution are7, 8and9.

ISSN:0018-019X    

DOI:10.1002/hlca.19700530405

出版商:WILEY‐VCH Verlag GmbH    

年代:1970

数据来源: WILEY

摘要:

AbstractThe glyceraldehyde formed by oxidation of glycerol through alcohol dehydrogenase (E.C. 1.1.1.1) from horse liver has been condensed with phosphodihydroxyacetone using either rabbit muscle or liver aldolase. The single product was identified after silylation by gas chromatography asL‐sorbose‐1‐phosphate. NoD‐fructose‐1‐phosphate was detected. Apparently liver alcohol dehydrogenase oxidizes glycerol stereospecifically toL‐(−)‐glyceraldehyde. Thus, the earlier conclusions ofHadorn et al.from chromatography of the borate complexes on Dowex 1 have been confirmed. The same stereospecific behavior was found for both isoenzymes III and IV.With Bis‐(trimethylsilyl)‐trifluoroacetamideL‐sorbose‐1‐phosphate andD‐fructose‐1‐phosphate are persilylated. Two trimethylsilyl groups are bound to the phosphate group. These bonds are not

ISSN:0018-019X    

DOI:10.1002/hlca.19700530406

出版商:WILEY‐VCH Verlag GmbH    

年代:1970

数据来源: WILEY

摘要:

AbstractCyclopentenones substituted in position 4, and 3, 5‐cisor ‐transdisubstituted cyclopentenes have been studied by NMR. and by IR. spectroscopy. Cyclopentenone derivatives and cyclopentene derivatives adopt a quasi‐coplanar and an envelope conformation, respectively. The preferential orientation of the substituents has been established according to their nature and to the solvents by correlation to the vicinal and the long‐range coupling co

ISSN:0018-019X    

DOI:10.1002/hlca.19700530407

出版商:WILEY‐VCH Verlag GmbH    

年代:1970

数据来源: WILEY

摘要:

AbstractThe alkaloid lonicerine was isolated fromCallichilia barteri(Apocynaceae). By chemical and spectroscopic evidence it could be shown to be 16‐epi‐aspidodasycarpine

ISSN:0018-019X    

DOI:10.1002/hlca.19700530408

出版商:WILEY‐VCH Verlag GmbH    

年代:1970

数据来源: WILEY

摘要:

AbstractThe synthesis of the antibiotic anisomycin (1) is described. In the key step 3, 4‐dimethoxy‐thiopyrrolidone (16), prepared from diethylL‐( + )‐tartarate (4) was converted to the thioiminoester18, which upon treatment with trimethylphosphite yielded the benzylidene derivative19. Cleavage of the ester group of19and hydrogenation of the decarboxylation product gave the two isomers21and22.22was converted into desacetylanisomycin (3) and anisomy

ISSN:0018-019X    

DOI:10.1002/hlca.19700530409

出版商:WILEY‐VCH Verlag GmbH    

年代:1970

数据来源: WILEY

摘要:

AbstractIn continuation of our study on new types of analgesics, we synthesized various hexahydro‐3‐benzazocines. The synthesis of these compounds, starting from well‐known intermediates, is described in this paper. The compounds do not exhibit biological activities worthy of further explor

ISSN:0018-019X    

DOI:10.1002/hlca.19700530410

出版商:WILEY‐VCH Verlag GmbH    

年代:1970

数据来源: WILEY

摘要:

AbstractThe oxidation of limonene with mercuric acetate gives a mixture containing mentha‐1. 3. 8‐triene, the hydrocarbon of parsley, and its isomer, mentha‐1. 4. 8‐triene. Selenium dioxide oxidation of limonene in alcohol gives as the main product mentha‐1. 8‐dien‐4‐ol, and pyrolysis of the acetate of the latter, or of mentha‐1. 8‐dien‐10‐yl acetate (the main product of the oxidation of limonene with selenium dioxide in acetic anhydride), also gives a mixture of menthatrienes. A discussion of the selenium dioxide oxidation o

ISSN:0018-019X    

DOI:10.1002/hlca.19700530411

出版商:WILEY‐VCH Verlag GmbH    

年代:1970

数据来源: WILEY