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Structural revision

How many different enolates may arise from deprotonation of 2,4-pentanedione Draw Lewis structures for each, and predict which is likely to be the most stable. Check your conclusions by examining the energies of the different possible enolates (enolate A, B...). Is the most stable enolate that derived from deprotonation of the most electron-poor hydrogen Compare the electrostatic potential maps of the anions with each other and with your Lewis structures. Revise your drawings to be consistent with the maps. Why is one of the enolates preferred over the others ... [Pg.163]

Scheme 3.11 Combinatorial use of CM and structural revision of AM3 by CM-degradation (PG = protecting group, Piv = pivaloyl, TBS = tert-butyl silyl)... Scheme 3.11 Combinatorial use of CM and structural revision of AM3 by CM-degradation (PG = protecting group, Piv = pivaloyl, TBS = tert-butyl silyl)...
Chart 2.3 Structural revision and biosynthesis analysis of nakiterpiosin... [Pg.32]

The following work presented by the Corey group describes the enan-tiospecific synthesis of the originally proposed structure of pseudopteroxazole (17). As the synthesized compoimd 48 was not identical with 17, the results of this study led to a structural revision yielding the correct stereochemistry of 17 [28]. The Corey group has also pubhshed a total synthesis of the pseudo-pterosin aglycones 11 [12] and 10 [29]. [Pg.21]

Bergeron RJ, Huang G, Smith RE, Bharti N, McManis JS, Butler A (2003) Total Synthesis and Structure Revision of Petrobactin. Tetrahedron 59 2007... [Pg.55]

Uria Fernandez D, Geoffroy V Schafer M, Meyer JM, Budzikiewicz H (2003) Structure Revision of Several Pyoverdines lYoduced by Plant-Growth Promoting and Plant-Deleterious Pseudomonas Species. Monatsh Chem 134 1421... [Pg.73]

Ghandler IM, McIntyre GR, Simpson TJ, Structural revision and synthesis of LL-D253 and related chromanone fungal metabolites, J Chem Soc Perkin Tans I 2271-2284, 1992. [Pg.468]

Scheme 63). The alternative structure (403) for the final product should also be considered in the light of the structural revision of the adduct obtained from thiourea and DMAD. ... [Pg.351]

Arimoto, H. Arimoto, Y. Okumura, S.N. Shosuke, Y. (1995) Synthetic studies on fiilly substituted y-pyrone-containing natural products total synthesis and structural revision of onchitriol I. Tetrahedron Lett., 36, 5357-8. [Pg.306]

Chen, H.F. et al., Tannins and related compounds. Part 121. Phenylpropanoid-substituted cate-chins from Castanopsis hystrix and structure revisions of cinchonains, Phytochemistry, 33, 183, 1993. [Pg.608]

Some remarks should be made regarding structures revised during the reporting period. A flavonol isolated from Glycyrrhiza lepidota, named glepidotin, had been ascribed the structure of 8-C-prenylgalangin. ° Comparison with the synthetic product and its isomer revealed that it is, in fact, 6-C-prenylgalangin (compound 78, Table 12.4). Noricaritin... [Pg.700]

Kinoshita, T., Tamura, Y., and Mizutani, K., Isolation and synthesis of two new 3-arylcoumarin derivatives from the root of Glycyrrhiza glabra (licorice), and structure revision of an antioxidant isoflavonoid glabrene, Natural Product Letters, 9, 289, 1997. [Pg.1189]

Tahara, S. et al.. Structure revision of piscidone, a major isoflavonoid in the root bark of Piscidia erythrina. Phytochemistry, 31, 679, 1992. [Pg.1194]

Lewis structures. Revise your drawings to be consistent... [Pg.252]

Kiyota, H., Dixon, D.J., Luscombe, C.K., Hettstedt, S. and Ley, S.V., Synthesis, structure revision, and absolute configuration of (+)-didemniserinolipid B, a serinol marine natural product from a Tunicate Didemnum sp., Org. Lett., 2002, 4, 3223. [Pg.171]

The Mexican sponge Aplysina gerardogreeni contains calafianin (2106) (1880) (structure revised and confirmed by total synthesis, (1881-1883)), the known aerothionin, and the new phenylacetic acid 2107 (1880). These studies confirm that calafianin (2106) and aerothionin have the same absolute configuration (1883). Whereas aerothionin displays antibacterial activity against Mycobacterium tuberculosis, calafianin does not (1884). The Brazilian sponge Aplysina caissara contains the new caissarines A (2108) and B (2109) (1885). [Pg.307]

The previously known chloropeptin 1 and complestatin (= chloropeptin II) have been the object of synthetic and stereochemical studies and structural revisions (2010-2012, 2653). The new complestatins A (2217) and B (2218) were characterized from a Streptomyces sp. MA7-234 (2013), and these two compounds would appear to be the same as neuroprotectins A and B isolated from Streptomyces sp. Q27107 (2014, 2015). Another Streptomyces sp. has... [Pg.330]

Usami Y, Horibe Y, Takaoka I, Ichikawa H, Arimoto M (2006) First Total Synthesis of (-)-Pericosine A from (-)-Shikimic Acid Structure Revision and Determination of the Absolute Configuration of Antitumour Natural Product Pericosine A. Synlett 1598... [Pg.397]

Makino B, Kawai M, Ogura T, Nakanishi M, Yamamura H, Butsugan Y (1995) Structural Revision of Physalin H Isolated from Physalis angulata. J Nat Prod 58 1668... [Pg.412]

Todd JS, Gerwick WH (1995) Malyngamide I from the Tropical Marine Cyanobacterium Lyngbya majuscula and the Probable Structure Revision of Stylocheilamide. Tetrahedron Lett 36 7837... [Pg.417]

Watanabe H, Okue M, Kobayashi H, Kitahara T (2002) The First Synthesis of Kaitocephalin Based on the Structure Revision. Tetrahedron Lett 43 861... [Pg.425]

Ogamino T, Nishiyama S (2005) Synthesis and Structure Revision of Calafianin, a Member of the Spiroisoxazole Family Isolated from the Marine Sponge, Aplysina gerardogreeni. Tetrahedron Lett 46 1083... [Pg.468]

Ogamino T, Obata R, Tomoda H, Nishiyama S (2006) Total Synthesis, Structure Revision, and Biological Evaluation of Calafianin, a Marine Spiroisoxazoline from the Sponge, Aplysina gerardogreeni. Bull Chem Soc Jpn 79 134... [Pg.468]

Carpenter J, Northrup AB, Chung dM, Wiener JJM, Kim S-G, MacMillan DWC (2008) Total Synthesis and Structural Revision of Callipeltoside C. Angew Chem Int Ed 47 3568... [Pg.504]

Bisbenzylisoquinoline alkaloids. Comprehensive tabulation of literature for 1978-1981 (Chemical Abstracts Volumes 88-95), with 164 references. Covers structure revisions, additional (mainly spectral) data on known alkaloids, new sources of known alkaloids, structures, properties, summarized confirmatory reactions of new alkaloids, and biosynthetic evidence. Alkaloids are tabulated by botanical sources and pharmacological activity. A section on methods (CD, luminescence spectra, specific rotation, TLC) is included. [Pg.155]

Several syntheses of phenanthridone derivatives related to the aromatization products of narciclasine and lycoricidine and apparently designed to further support the structural revision have been completed. In a photochemical synthesis starting from 368 the compound 360 was obtained yielding on debenzylation narciprimine (356), whereas from 369 in an analogous way arolycoricidine (361) was prepared. Also, starting from the amide 370 through photocyclization to 362 via 363 a compound identical with natural permethylisonarciprimine (357) was obtained (81). [Pg.143]

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See also in sourсe #XX -- [ Pg.475 ]



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Methods structural revision

Proof of the Revised Structure

Revised

Revised Control Structure

Revisions

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