homologues with hydroxylamine were found to give 4-nitro-5(2H)-isoxazolone. These results were rationalized by double ring transformations in sequence. The fact that the 4-position of the 4-pyridone behaved as an electrophlic site was the first example in this series of ring transfomations, and was caused by the alpha-effect of the reagent. Some reactions of the isoxazolone were carried out.
Synthesis of bicyclic pyrazinones via addition of heterocyclic amines to a nitro-alkene
作者:Margaret A. Brimble、Andrew D. Johnston
DOI:10.1016/s0040-4020(01)85023-7
日期:1994.4
Michael addition of heterocyclic amines (6), (10), (13) and (17) to nitro-olefin (3) followed by reduction/cyclization of the nitro group of the adduct provides a convenient synthesis of the bicyclic pyrazinones (8), (12), (16), (19) and (20) which are found in several natural products.
The preparation of racemic and optically pure tryptophans is described. The D-enantiomers of the 6-substituted compounds possess a potent sweetening capability. Novel intermediates are also disclosed.
The preparation of racemic and optically pure tryptophans is described. The D-enantiomers of the 6-substituted compounds possess a potent sweetening capability. Novel intermediates are also disclosed.
Lower alkyl esters of .alpha.-formamido,.alpha.-carbalkoxy tryptophans
申请人:Hoffmann-La Roche Inc.
公开号:US04140697A1
公开(公告)日:1979-02-20
Lower alkyl esters of 2-formamido-3(4,5,6 or 7-methyl substituted-3-indolyl)-2-carbalkoxy propionic acid which are useful as intermediates for tryptophane sweetners.