The present invention pertains, at least in part, to novel substituted tetracycline compounds. These tetracycline compounds can be used to treat numerous tetracycline compound-responsive states, such as bacterial infections and neoplasms.
Synthesis of [1]Benzopyrano[4,3-<i>b</i>]pyrrol-4(1<i>H</i>)-ones from 4-Chlorocoumarin
作者:Ángel Alberola、Rocío Álvaro、José M. Andrés、Blanca Calvo、Alfonso González
DOI:10.1055/s-1994-25459
日期:——
4-N-(Acylmethyl)aminocoumarins or their ketal derivatives were prepared from 4-chlorocoumarin and α-amino ketones (chlorohydrates or ketal derivatives) in ethanol/triethylamine media. Their subsequent treatment in acidic or basic media readily led to [1] benzopyrano[4,3-b] pyrrol-4(1H)-ones.
Rhodium-Catalyzed Domino Enantioselective Synthesis of Bicyclo[2.2.2]lactones
作者:Alistair Boyer、Mark Lautens
DOI:10.1002/anie.201101773
日期:2011.8.1
Once, twice, three times a catalyst! A novel domino rhodium(I)‐catalyzed asymmetric transformation of substituted oxabicyclic alkenes into bicyclo[2.2.2]lactones proceeded with good yields (up to 78 %) and excellent stereoselectivity (>97 % ee; see scheme; cod=1,5‐cyclooctadiene, Tf=trifluoromethanesulfonyl). Mechanistic investigations suggest that this process proceeds by rhodium‐catalyzed asymmetric
作者:Edmund C. Kornfeld、E. J. Fornefeld、G. Bruce Kline、Marjorie J. Mann、Dwight E. Morrison、Reuben G. Jones、R. B. Woodward
DOI:10.1021/ja01594a039
日期:1956.7
immunological homogeneity it has been established by several investigators that proteins which are non-homogeneous in the ultracentrifuge, electrophoretically and in amino acid composition may be immunochemically uniform. The relationship of amino acid composition to specificity among the blood group substances is not clear from the data presented. Work on the inhibition by oligosaccharides of the precipitation
Synthesis of [1]Benzopyrano[4,3-b]pyrrol-4(1H)-ones from 4-Chloro-3-formylcoumarin
作者:Angel Alberola、Luis Calvo、Alfonso González-Ortega、Alfonso P. Encabo、M. Carmen Sañudo
DOI:10.1055/s-2001-17696
日期:——
2-Functionalized [1]benzopyrano[4,3-b]pyrrol-4(1H)-ones were obtained by the Fischer-Fink reaction starting from 4-chloro-3-formylcoumarin and different α-amino derivatives (e.g. glycinonitriles, ethyl glycinates and α-amino ketones). In general limitations to the synthetic method arise when α-amino derivatives with very reactive functions were used (e.g. carboxaldehyde groups or their acetal derivatives) leading to Knorr type reactions, or when they contain relatively inactive methylenes (e.g. carboxamide groups) which failed to complete the cyclization process.