Zobrazeno 1 - 9
of 9
pro vyhledávání: '"Hans Fritz"'
Publikováno v:
Tetrahedron. 46:1211-1220
Zusammenfassung A concept for the synthesis of C'- homovinblastine derivative 1 is presented in which the azecinoindole derivative 3 and the bicyclic lactam 5 are key intermediates. Starting from tryptamine, the synthesis of these two intermediates i
Publikováno v:
Tetrahedron. 46:1221-1230
Coupling of the acezinoindole derivative 1a with N,N-dimethyl-m-anisidine via the corresponding chloroindolenine results, after cyclization, in the formation of an 1:1 mixture of the homocleavamine derivatives 3I and 3II . The corresponding reaction
Publikováno v:
Tetrahedron. 43:3747-3763
Zusammenfassung In a new concept for the synthesis of 20'-deethyl-20'-deoxyvin-blastine, Nb-seco-cleavamine derivatives 1a , 2a are possible precursors. For the synthesis of these compounds the indolizino(5,4-b]indoles 8I , II were treated with benzy
Publikováno v:
Tetrahedron. 38:3753-3760
4-Substituted-1,2-diphenyl-3,5-pyrazolidinediones (Phenylbutazone analogous) 1a–d react with 2,4-bi-(4-methoxyphenyl)-1,3,2,4-dithiadiphosphetane 2,4-difulside (Lawesson Reagent (LR) with formation of the corresponding 3,3′-dithiobis (1,2-dihydro
Publikováno v:
Tetrahedron. 32:1055-1059
The position of the trifluoroacetyl group in mesoionic 2,3-diaryl-5-imino oxazolines has been disputed. The natural abundance 13 C NMR spectra and the 1,3-dipolar cycloaddition product of the mesoionic oxazoline with the dimethylacetylenedicarboxylat
Publikováno v:
Tetrahedron. 32:3031-3039
Resume Les esters acetyleniques reagissent sur la base de Fischer (trimethyl-1,3-3 methylene-2 indoline) pour conduire a un intermediaire zwitterionique qui evolue dans le MeOH vers un produit d'addition du type Michael, et dans le CHCl 3 vers une di
Publikováno v:
Tetrahedron. 43:3729-3745
Starting from vindoline ( 2 ) and 7-methoxycarbonylazoninoindole derivatives 7 , a new concept for the synthesis of vinblastine 1a type alkaloids with natural C(16') stereochemistry is described. Using lactam 8 and chloroindolenine 9 as key intermedi
Publikováno v:
Tetrahedron. 43:3765-3786
Coupling of racemic 16-methoxycarbonyl-15,20-dihydro-3,Nb-seco-cleavamine derivative 34 with (-)vindoline via chloroindolenine intermediate 41 occurs with high stereoselectivity and leads after cyclization to the separable dimers 46I and 46II with na
Publikováno v:
Tetrahedron. 33:1349-1351
A new heterocyclic system, 1,2,9-triaza-8-oxabicyclo-[5.3.0]-3,5,9-decatriene 4 , has been synthesized by regiospecific 1,3-dipolar cycloaddition of nitrile oxides to the imine double bond of 1,2-diazepines. Bis-adduct 5a is obtained in only trace am