ISSN:
0018-019X
Schlagwort(e):
Chemistry
;
Organic Chemistry
Quelle:
Wiley InterScience Backfile Collection 1832-2000
Thema:
Chemie und Pharmazie
Notizen:
The oxidative transformation of (+)-aristoteline ((+)-5) into its metabolites, the recently synthesized indole alkaloids (-)-serratoline ((-)-6), (+)-aristotelone ((+)-2), and (-)-alloaristoteline ((-)-22), was investigated in more detail. It was demonstrated that the diastereoface selectivity of the reaction of (+)-5 with 3-chloroperbenzoic acid can be altered by variation of the solvent as well as by addition of CF3COOH. The chemoselectivity of the 1,2-rearrangement of the intermediate 3H-indol-3-ol derivatives could be controlled as follows: treatment of 3H-indol-3-ols with aqueous polyphosphoric acid led to the pseudoindoxyl ( = 1,2-dihydro-3H-indol-3-one) derivatives, whereas an analogous treatment of the corresponding O-benzoates furnished exclusively the corresponding, constitutionally isomeric 2-oxindole ( = 1,3-dihydro-2H-indol-2-one) products. Exploitation of these and related findings led to efficient total syntheses of the Aristotelia alkaloid (-)-tasmanine ((-)-1) and of the corresponding unnatural epimer (+)-12, as well as of the two pseudoindoxyls (+)-aristotelone ((+)-2) and (-)-2-epiaristotelone ((-)-11). All these transformations were carried out with synthetic (+)-aristoteline ((+)-5) as the single indole alkaloid precursor.
Zusätzliches Material:
1 Ill.
Materialart:
Digitale Medien
URL:
http://dx.doi.org/10.1002/hlca.19930760505
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