نتایج جستجو برای: bicyclo
تعداد نتایج: 1233 فیلتر نتایج به سال:
Disproving a long C-C-bond textbook example: The reported 1.643 Å C-C bond in 5-cyano-1,3-dehydroadamantane was redetermined and "only" amounts to 1.584 Å. While this value is well reproduced with ab initio methods, some common DFT approaches perform poorly and are only consistent with CCSD(T)/cc-pVTZ optimizations for noninverted carbons. Large deviations from experiment were also found for ot...
Prostaglandins (PGs) are important mediators of macrophage activity, vascular permeability, fever, erythropoiesis, and proinflammatory responses to infection. Our recent studies have shown that plasma levels of bicyclo-PGE2 (a stable end product of PGE2 metabolism) and leukocyte cyclooxygenase (COX)-2 gene expression are suppressed in children with malarial anemia. Since the role of PGs as immu...
As a part of our ongoing synthetic quest to expand the frontiers of contemporary medicinal chemistry, we now report an expedient synthesis of a potentially useful bicyclo[1.1.1]pentane building block, 3-(pyrazin-2-yl)bicyclo[1.1.1]pentane-1-carboxylic acid. This report also showcases the application of this motif as a probe in a biological study.
Bicyclo[2.1.1]hexanes (BCHs) represent an intriguing class of structurally rigid hydrocarbons that can serve as the bioisosteres benzenoids in medicinal chemistry. Methods for synthesis BCHs are, however, limiting. Reported herein is a facile via strain-release-driven [2π + 2σ] cycloaddition bicyclo[1.1.0]butanes (BCBs) with alkenes facilitated by pyridine-boryl radical catalyst. The mild react...
A series of β,β'-bicyclo-3,5-diaryl-BODIPYs were synthesized from the corresponding β,β'-bicyclo-3,5-diiodo-BODIPYs (1a,b) via Pd(0)-mediated Suzuki cross-coupling reactions in 82-92% yields. Subsequent aromatization with DDQ afforded the corresponding β,β'-dibenzo-aryl-BODIPYs, which showed red-shifted absorptions and emissions in the near-IR range. The dibenzo-appended BODIPYs showed characte...
Pallescensins are a group of furanosesquiterpenoids isolated from the marine sponge Disidea pallescens by Cimino et al.1 The common feature of these terpenoids is that they all contain a furan moiety; however they have carbon skeletons of varying complexity. Among the pallescensins, pallescensin B 1 presents the most complex architecture, with a unique bicyclo[4.2.2]decane system fused to a fur...
Prostaglandins (PGs) derived from inducible cyclooxygenase (COX)-2 are important proinflammatory mediators of the host-immune response to infection. Since the role of host-derived PG in human malaria is unknown, plasma bicyclo-PGE2 (a stable catabolite of PGE2), peripheral blood mononuclear cell COX-2 protein, and mRNA were measured in Gabonese children with and without malaria (n=129). Relativ...
the condensation of glyoxal with benzylamine in the presence of formaldehyde leads to 2,4,6,8-tetrabenzyl-2,4,6,8-tetraazabicyclo [3.3.0] octan (6) in methanol. the scopes and limitations of the reaction have been determined. at low temperatures, a mixture of (6) and diol (7) is formed.
The reaction of furylacrylic acid with cyclopentadiene in toluene gave the expected Diels-Alder endo-and exo-adductsin -1 : 1 ratio. The adducts were separated by iodolactonization method to provide 3-endo-(2'-furyl) bicyclo 12.2.11 hept-5-ene- 2-exo-carboxylic acid and 3-exo-(2'-fury1)bicyclo 12.2.11 hept-5-ene-2-endocarboxylic acid. Esterification of these acids by MeI / HMPA gave the exp...
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